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 <head>
  <meta content="text/html; charset=utf-8" http-equiv="Content-Type">
  <title>WebUSB Testing API</title>
  <meta content="width=device-width, initial-scale=1, shrink-to-fit=no" name="viewport">
<style data-fill-with="stylesheet">/******************************************************************************
 *                   Style sheet for the W3C specifications                   *
 *
 * Special classes handled by this style sheet include:
 *
 * Indices
 *   - .toc for the Table of Contents (<ol class="toc">)
 *     + <span class="secno"> for the section numbers
 *   - #toc for the Table of Contents (<nav id="toc">)
 *   - ul.index for Indices (<a href="#ref">term</a><span>, in §N.M</span>)
 *   - table.index for Index Tables (e.g. for properties or elements)
 *
 * Structural Markup
 *   - table.data for general data tables
 *     -> use 'scope' attribute, <colgroup>, <thead>, and <tbody> for best results !
 *     -> use <table class='complex data'> for extra-complex tables
 *     -> use <td class='long'> for paragraph-length cell content
 *     -> use <td class='pre'> when manual line breaks/indentation would help readability
 *   - dl.switch for switch statements
 *   - ol.algorithm for algorithms (helps to visualize nesting)
 *   - .figure and .caption (HTML4) and figure and figcaption (HTML5)
 *     -> .sidefigure for right-floated figures
 *   - ins/del
 *
 * Code
 *   - pre and code
 *
 * Special Sections
 *   - .note       for informative notes             (div, p, span, aside, details)
 *   - .example    for informative examples          (div, p, pre, span)
 *   - .issue      for issues                        (div, p, span)
 *   - .assertion  for assertions                    (div, p, span)
 *   - .advisement for loud normative statements     (div, p, strong)
 *   - .annoying-warning for spec obsoletion notices (div, aside, details)
 *
 * Definition Boxes
 *   - pre.def   for WebIDL definitions
 *   - table.def for tables that define other entities (e.g. CSS properties)
 *   - dl.def    for definition lists that define other entitles (e.g. HTML elements)
 *
 * Numbering
 *   - .secno for section numbers in .toc and headings (<span class='secno'>3.2</span>)
 *   - .marker for source-inserted example/figure/issue numbers (<span class='marker'>Issue 4</span>)
 *   - ::before styled for CSS-generated issue/example/figure numbers:
 *     -> Documents wishing to use this only need to add
 *        figcaption::before,
 *        .caption::before { content: "Figure "  counter(figure) " ";  }
 *        .example::before { content: "Example " counter(example) " "; }
 *        .issue::before   { content: "Issue "   counter(issue) " ";   }
 *
 * Header Stuff (ignore, just don't conflict with these classes)
 *   - .head for the header
 *   - .copyright for the copyright
 *
 * Miscellaneous
 *   - .overlarge for things that should be as wide as possible, even if
 *     that overflows the body text area. This can be used on an item or
 *     on its container, depending on the effect desired.
 *     Note that this styling basically doesn't help at all when printing,
 *     since A4 paper isn't much wider than the max-width here.
 *     It's better to design things to fit into a narrower measure if possible.
 *   - js-added ToC jump links (see fixup.js)
 *
 ******************************************************************************/

/******************************************************************************/
/*                                   Body                                     */
/******************************************************************************/

	body {
		counter-reset: example figure issue;

		/* Layout */
		max-width: 50em;               /* limit line length to 50em for readability   */
		margin: 0 auto;                /* center text within page                     */
		padding: 1.6em 1.5em 2em 50px; /* assume 16px font size for downlevel clients */
		padding: 1.6em 1.5em 2em calc(26px + 1.5em); /* leave space for status flag     */

		/* Typography */
		line-height: 1.5;
		font-family: sans-serif;
		widows: 2;
		orphans: 2;
		word-wrap: break-word;
		overflow-wrap: break-word;
		hyphens: auto;

		/* Colors */
		color: black;
		background: white top left fixed no-repeat;
		background-size: 25px auto;
	}


/******************************************************************************/
/*                         Front Matter & Navigation                          */
/******************************************************************************/

/** Header ********************************************************************/

	div.head { margin-bottom: 1em }
	div.head hr { border-style: solid; }

	div.head h1 {
		font-weight: bold;
		margin: 0 0 .1em;
		font-size: 220%;
	}

	div.head h2 { margin-bottom: 1.5em;}

/** W3C Logo ******************************************************************/

	.head .logo {
		float: right;
		margin: 0.4rem 0 0.2rem .4rem;
	}

	.head img[src*="logos/W3C"] {
		display: block;
		border: solid #1a5e9a;
		border-width: .65rem .7rem .6rem;
		border-radius: .4rem;
		background: #1a5e9a;
		color: white;
		font-weight: bold;
	}

	.head a:hover > img[src*="logos/W3C"],
	.head a:focus > img[src*="logos/W3C"] {
		opacity: .8;
	}

	.head a:active > img[src*="logos/W3C"] {
		background: #c00;
		border-color: #c00;
	}

	/* see also additional rules in Link Styling section */

/** Copyright *****************************************************************/

	p.copyright,
	p.copyright small { font-size: small }

/** Back to Top / ToC Toggle **************************************************/

	@media print {
		#toc-nav {
			display: none;
		}
	}
	@media not print {
		#toc-nav {
			position: fixed;
			z-index: 2;
			bottom: 0; left: 0;
			margin: 0;
			min-width: 1.33em;
			border-top-right-radius: 2rem;
			box-shadow: 0 0 2px;
			font-size: 1.5em;
			color: black;
		}
		#toc-nav > a {
			display: block;
			white-space: nowrap;

			height: 1.33em;
			padding: .1em 0.3em;
			margin: 0;

			background: white;
			box-shadow: 0 0 2px;
			border: none;
			border-top-right-radius: 1.33em;
			background: white;
		}
		#toc-nav > #toc-jump {
			padding-bottom: 2em;
			margin-bottom: -1.9em;
		}

		#toc-nav > a:hover,
		#toc-nav > a:focus {
			background: #f8f8f8;
		}
		#toc-nav > a:not(:hover):not(:focus) {
			color: #707070;
		}

		/* statusbar gets in the way on keyboard focus; remove once browsers fix */
		#toc-nav > a[href="#toc"]:not(:hover):focus:last-child {
			padding-bottom: 1.5rem;
		}

		#toc-nav:not(:hover) > a:not(:focus) > span + span {
			/* Ideally this uses :focus-within on #toc-nav */
			display: none;
		}
		#toc-nav > a > span + span {
			padding-right: 0.2em;
		}

		#toc-toggle-inline {
			vertical-align: 0.05em;
			font-size: 80%;
			color: gray;
			color: hsla(203,20%,40%,.7);
			border-style: none;
			background: transparent;
			position: relative;
		}
		#toc-toggle-inline:hover:not(:active),
		#toc-toggle-inline:focus:not(:active) {
			text-shadow: 1px 1px silver;
			top: -1px;
			left: -1px;
		}

		#toc-nav :active {
			color: #C00;
		}
	}

/** ToC Sidebar ***************************************************************/

	/* Floating sidebar */
	@media screen {
		body.toc-sidebar #toc {
			position: fixed;
			top: 0; bottom: 0;
			left: 0;
			width: 23.5em;
			max-width: 80%;
			max-width: calc(100% - 2em - 26px);
			overflow: auto;
			padding: 0 1em;
			padding-left: 42px;
			padding-left: calc(1em + 26px);
			background: inherit;
			background-color: #f7f8f9;
			z-index: 1;
			box-shadow: -.1em 0 .25em rgba(0,0,0,.1) inset;
		}
		body.toc-sidebar #toc h2 {
			margin-top: .8rem;
			font-variant: small-caps;
			font-variant: all-small-caps;
			text-transform: lowercase;
			font-weight: bold;
			color: gray;
			color: hsla(203,20%,40%,.7);
		}
		body.toc-sidebar #toc-jump:not(:focus) {
			width: 0;
			height: 0;
			padding: 0;
			position: absolute;
			overflow: hidden;
		}
	}
	/* Hide main scroller when only the ToC is visible anyway */
	@media screen and (max-width: 28em) {
		body.toc-sidebar {
			overflow: hidden;
		}
	}

	/* Sidebar with its own space */
	@media screen and (min-width: 78em) {
		body:not(.toc-inline) #toc {
			position: fixed;
			top: 0; bottom: 0;
			left: 0;
			width: 23.5em;
			overflow: auto;
			padding: 0 1em;
			padding-left: 42px;
			padding-left: calc(1em + 26px);
			background: inherit;
			background-color: #f7f8f9;
			z-index: 1;
			box-shadow: -.1em 0 .25em rgba(0,0,0,.1) inset;
		}
		body:not(.toc-inline) #toc h2 {
			margin-top: .8rem;
			font-variant: small-caps;
			font-variant: all-small-caps;
			text-transform: lowercase;
			font-weight: bold;
			color: gray;
			color: hsla(203,20%,40%,.7);
		}

		body:not(.toc-inline) {
			padding-left: 29em;
		}
		/* See also Overflow section at the bottom */

		body:not(.toc-inline) #toc-jump:not(:focus) {
			width: 0;
			height: 0;
			padding: 0;
			position: absolute;
			overflow: hidden;
		}
	}
	@media screen and (min-width: 90em) {
		body:not(.toc-inline) {
			margin: 0 4em;
		}
	}

/******************************************************************************/
/*                                Sectioning                                  */
/******************************************************************************/

/** Headings ******************************************************************/

	h1, h2, h3, h4, h5, h6, dt {
		page-break-after: avoid;
		page-break-inside: avoid;
		font: 100% sans-serif;   /* Reset all font styling to clear out UA styles */
		font-family: inherit;    /* Inherit the font family. */
		line-height: 1.2;        /* Keep wrapped headings compact */
		hyphens: manual;         /* Hyphenated headings look weird */
	}

	h2, h3, h4, h5, h6 {
		margin-top: 3rem;
	}

	h1, h2, h3 {
		color: #005A9C;
		background: transparent;
	}

	h1 { font-size: 170%; }
	h2 { font-size: 140%; }
	h3 { font-size: 120%; }
	h4 { font-weight: bold; }
	h5 { font-style: italic; }
	h6 { font-variant: small-caps; }
	dt { font-weight: bold; }

/** Subheadings ***************************************************************/

	h1 + h2,
	#subtitle {
		/* #subtitle is a subtitle in an H2 under the H1 */
		margin-top: 0;
	}
	h2 + h3,
	h3 + h4,
	h4 + h5,
	h5 + h6 {
		margin-top: 1.2em; /* = 1 x line-height */
	}

/** Section divider ***********************************************************/

	:not(.head) > hr {
		font-size: 1.5em;
		text-align: center;
		margin: 1em auto;
		height: auto;
		border: transparent solid 0;
		background: transparent;
	}
	:not(.head) > hr::before {
		content: "\2727\2003\2003\2727\2003\2003\2727";
	}

/******************************************************************************/
/*                            Paragraphs and Lists                            */
/******************************************************************************/

	p {
		margin: 1em 0;
	}

	dd > p:first-child,
	li > p:first-child {
		margin-top: 0;
	}

	ul, ol {
		margin-left: 0;
		padding-left: 2em;
	}

	li {
		margin: 0.25em 0 0.5em;
		padding: 0;
	}

	dl dd {
		margin: 0 0 .5em 2em;
	}

	.head dd + dd { /* compact for header */
		margin-top: -.5em;
	}

	/* Style for algorithms */
	ol.algorithm ol:not(.algorithm),
	.algorithm > ol ol:not(.algorithm) {
	 border-left: 0.5em solid #DEF;
	}

	/* Put nice boxes around each algorithm. */
	[data-algorithm]:not(.heading) {
	  padding: .5em;
	  border: thin solid #ddd; border-radius: .5em;
	  margin: .5em calc(-0.5em - 1px);
	}
	[data-algorithm]:not(.heading) > :first-child {
	  margin-top: 0;
	}
	[data-algorithm]:not(.heading) > :last-child {
	  margin-bottom: 0;
	}

	/* Style for switch/case <dl>s */
	dl.switch > dd > ol.only,
	dl.switch > dd > .only > ol {
	 margin-left: 0;
	}
	dl.switch > dd > ol.algorithm,
	dl.switch > dd > .algorithm > ol {
	 margin-left: -2em;
	}
	dl.switch {
	 padding-left: 2em;
	}
	dl.switch > dt {
	 text-indent: -1.5em;
	 margin-top: 1em;
	}
	dl.switch > dt + dt {
	 margin-top: 0;
	}
	dl.switch > dt::before {
	 content: '\21AA';
	 padding: 0 0.5em 0 0;
	 display: inline-block;
	 width: 1em;
	 text-align: right;
	 line-height: 0.5em;
	}

/** Terminology Markup ********************************************************/


/******************************************************************************/
/*                                 Inline Markup                              */
/******************************************************************************/

/** Terminology Markup ********************************************************/
	dfn   { /* Defining instance */
		font-weight: bolder;
	}
	a > i { /* Instance of term */
		font-style: normal;
	}
	dt dfn code, code.idl {
		font-size: medium;
	}
	dfn var {
		font-style: normal;
	}

/** Change Marking ************************************************************/

	del { color: red;  text-decoration: line-through; }
	ins { color: #080; text-decoration: underline;    }

/** Miscellaneous improvements to inline formatting ***************************/

	sup {
		vertical-align: super;
		font-size: 80%
	}

/******************************************************************************/
/*                                    Code                                    */
/******************************************************************************/

/** General monospace/pre rules ***********************************************/

	pre, code, samp {
		font-family: Menlo, Consolas, "DejaVu Sans Mono", Monaco, monospace;
		font-size: .9em;
		page-break-inside: avoid;
		hyphens: none;
		text-transform: none;
	}
	pre code,
	code code {
		font-size: 100%;
	}

	pre {
		margin-top: 1em;
		margin-bottom: 1em;
		overflow: auto;
	}

/** Inline Code fragments *****************************************************/

  /* Do something nice. */

/******************************************************************************/
/*                                    Links                                   */
/******************************************************************************/

/** General Hyperlinks ********************************************************/

	/* We hyperlink a lot, so make it less intrusive */
	a[href] {
		color: #034575;
		text-decoration: none;
		border-bottom: 1px solid #707070;
		/* Need a bit of extending for it to look okay */
		padding: 0 1px 0;
		margin: 0 -1px 0;
	}
	a:visited {
		border-bottom-color: #BBB;
	}

	/* Use distinguishing colors when user is interacting with the link */
	a[href]:focus,
	a[href]:hover {
		background: #f8f8f8;
		background: rgba(75%, 75%, 75%, .25);
		border-bottom-width: 3px;
		margin-bottom: -2px;
	}
	a[href]:active {
		color: #C00;
		border-color: #C00;
	}

	/* Backout above styling for W3C logo */
	.head .logo,
	.head .logo a {
		border: none;
		text-decoration: none;
		background: transparent;
	}

/******************************************************************************/
/*                                    Images                                  */
/******************************************************************************/

	img {
		border-style: none;
	}

	/* For autogen numbers, add
	   .caption::before, figcaption::before { content: "Figure " counter(figure) ". "; }
	*/

	figure, .figure, .sidefigure {
		page-break-inside: avoid;
		text-align: center;
		margin: 2.5em 0;
	}
	.figure img,    .sidefigure img,    figure img,
	.figure object, .sidefigure object, figure object {
		max-width: 100%;
		margin: auto;
	}
	.figure pre, .sidefigure pre, figure pre {
		text-align: left;
		display: table;
		margin: 1em auto;
	}
	.figure table, figure table {
		margin: auto;
	}
	@media screen and (min-width: 20em) {
		.sidefigure {
			float: right;
			width: 50%;
			margin: 0 0 0.5em 0.5em
		}
	}
	.caption, figcaption, caption {
		font-style: italic;
		font-size: 90%;
	}
	.caption::before, figcaption::before, figcaption > .marker {
		font-weight: bold;
	}
	.caption, figcaption {
		counter-increment: figure;
	}

	/* DL list is indented 2em, but figure inside it is not */
	dd > .figure, dd > figure { margin-left: -2em }

/******************************************************************************/
/*                             Colored Boxes                                  */
/******************************************************************************/

	.issue, .note, .example, .assertion, .advisement, blockquote {
		padding: .5em;
		border: .5em;
		border-left-style: solid;
		page-break-inside: avoid;
	}
	span.issue, span.note {
		padding: .1em .5em .15em;
		border-right-style: solid;
	}

	.issue,
	.note,
	.example,
	.advisement,
	.assertion,
	blockquote {
		margin: 1em auto;
	}
	.note  > p:first-child,
	.issue > p:first-child,
	blockquote > :first-child {
		margin-top: 0;
	}
	blockquote > :last-child {
		margin-bottom: 0;
	}

/** Blockquotes ***************************************************************/

	blockquote {
		border-color: silver;
	}

/** Open issue ****************************************************************/

	.issue {
		border-color: #E05252;
		background: #FBE9E9;
		counter-increment: issue;
		overflow: auto;
	}
	.issue::before, .issue > .marker {
		text-transform: uppercase;
		color: #AE1E1E;
		padding-right: 1em;
		text-transform: uppercase;
	}
	/* Add .issue::before { content: "Issue " counter(issue) " "; } for autogen numbers,
	   or use class="marker" to mark up the issue number in source. */

/** Example *******************************************************************/

	.example {
		border-color: #E0CB52;
		background: #FCFAEE;
		counter-increment: example;
		overflow: auto;
		clear: both;
	}
	.example::before, .example > .marker {
		text-transform: uppercase;
		color: #827017;
		min-width: 7.5em;
		display: block;
	}
	/* Add .example::before { content: "Example " counter(example) " "; } for autogen numbers,
	   or use class="marker" to mark up the example number in source. */

/** Non-normative Note ********************************************************/

	.note {
		border-color: #52E052;
		background: #E9FBE9;
		overflow: auto;
	}

	.note::before, .note > .marker,
	details.note > summary::before,
	details.note > summary > .marker {
		text-transform: uppercase;
		display: block;
		color: hsl(120, 70%, 30%);
	}
	/* Add .note::before { content: "Note"; } for autogen label,
	   or use class="marker" to mark up the label in source. */

	details.note > summary {
		display: block;
		color: hsl(120, 70%, 30%);
	}
	details.note[open] > summary {
		border-bottom: 1px silver solid;
	}

/** Assertion Box *************************************************************/
	/*  for assertions in algorithms */

	.assertion {
		border-color: #AAA;
		background: #EEE;
	}

/** Advisement Box ************************************************************/
	/*  for attention-grabbing normative statements */

	.advisement {
		border-color: orange;
		border-style: none solid;
		background: #FFEECC;
	}
	strong.advisement {
		display: block;
		text-align: center;
	}
	.advisement > .marker {
		color: #B35F00;
	}

/** Spec Obsoletion Notice ****************************************************/
	/* obnoxious obsoletion notice for older/abandoned specs. */

	details {
		display: block;
	}
	summary {
		font-weight: bolder;
	}

	.annoying-warning:not(details),
	details.annoying-warning:not([open]) > summary,
	details.annoying-warning[open] {
		background: #fdd;
		color: red;
		font-weight: bold;
		padding: .75em 1em;
		border: thick red;
		border-style: solid;
		border-radius: 1em;
	}
	.annoying-warning :last-child {
		margin-bottom: 0;
	}

@media not print {
	details.annoying-warning[open] {
		position: fixed;
		left: 1em;
		right: 1em;
		bottom: 1em;
		z-index: 1000;
	}
}

	details.annoying-warning:not([open]) > summary {
		text-align: center;
	}

/** Entity Definition Boxes ***************************************************/

	.def {
		padding: .5em 1em;
		background: #DEF;
		margin: 1.2em 0;
		border-left: 0.5em solid #8CCBF2;
	}

/******************************************************************************/
/*                                    Tables                                  */
/******************************************************************************/

	th, td {
		text-align: left;
		text-align: start;
	}

/** Property/Descriptor Definition Tables *************************************/

	table.def {
		/* inherits .def box styling, see above */
		width: 100%;
		border-spacing: 0;
	}

	table.def td,
	table.def th {
		padding: 0.5em;
		vertical-align: baseline;
		border-bottom: 1px solid #bbd7e9;
	}

	table.def > tbody > tr:last-child th,
	table.def > tbody > tr:last-child td {
		border-bottom: 0;
	}

	table.def th {
		font-style: italic;
		font-weight: normal;
		padding-left: 1em;
		width: 3em;
	}

	/* For when values are extra-complex and need formatting for readability */
	table td.pre {
		white-space: pre-wrap;
	}

	/* A footnote at the bottom of a def table */
	table.def           td.footnote {
		padding-top: 0.6em;
	}
	table.def           td.footnote::before {
		content: " ";
		display: block;
		height: 0.6em;
		width: 4em;
		border-top: thin solid;
	}

/** Data tables (and properly marked-up index tables) *************************/
	/*
		 <table class="data"> highlights structural relationships in a table
		 when correct markup is used (e.g. thead/tbody, th vs. td, scope attribute)

		 Use class="complex data" for particularly complicated tables --
		 (This will draw more lines: busier, but clearer.)

		 Use class="long" on table cells with paragraph-like contents
		 (This will adjust text alignment accordingly.)
		 Alternately use class="longlastcol" on tables, to have the last column assume "long".
	*/

	table {
		word-wrap: normal;
		overflow-wrap: normal;
		hyphens: manual;
	}

	table.data,
	table.index {
		margin: 1em auto;
		border-collapse: collapse;
		border: hidden;
		width: 100%;
	}
	table.data caption,
	table.index caption {
		max-width: 50em;
		margin: 0 auto 1em;
	}

	table.data td,  table.data th,
	table.index td, table.index th {
		padding: 0.5em 1em;
		border-width: 1px;
		border-color: silver;
		border-top-style: solid;
	}

	table.data thead td:empty {
		padding: 0;
		border: 0;
	}

	table.data  thead,
	table.index thead,
	table.data  tbody,
	table.index tbody {
		border-bottom: 2px solid;
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/*
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*/

/******************************************************************************/
/*                                  Indices                                   */
/******************************************************************************/


/** Table of Contents *********************************************************/

	.toc a {
		/* More spacing; use padding to make it part of the click target. */
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		/* Larger, more consistently-sized click target */
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/******************************************************************************/
/*                                    Print                                   */
/******************************************************************************/

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		/* Serif for print. */
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			font-family: serif;
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	@page {
		margin: 1.5cm 1.1cm;
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/******************************************************************************/
/*                                    Legacy                                  */
/******************************************************************************/

	/* This rule is inherited from past style sheets. No idea what it's for. */
	.hide { display: none }



/******************************************************************************/
/*                             Overflow Control                               */
/******************************************************************************/

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a.self-link::before            { content: "¶"; }
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</style>
 <body class="h-entry">
  <div class="head">
   <p data-fill-with="logo"></p>
   <h1 class="p-name no-ref" id="title">WebUSB Testing API</h1>
   <h2 class="no-num no-toc no-ref heading settled" id="subtitle"><span class="content">Editor’s Draft, <time class="dt-updated" datetime="1970-01-01">1 January 1970</time></span></h2>
   <div data-fill-with="spec-metadata">
    <dl>
     <dt>This version:
     <dd><a class="u-url" href="https://wicg.github.io/webusb/test/">https://wicg.github.io/webusb/test/</a>
     <dt class="editor">Editors:
     <dd class="editor p-author h-card vcard" data-editor-id="83788"><a class="p-name fn u-email email" href="mailto:reillyg@google.com">Reilly Grant</a> (<a class="p-org org" href="https://www.google.com">Google LLC</a>)
     <dd class="editor p-author h-card vcard" data-editor-id="106543"><a class="p-name fn u-email email" href="mailto:odejesush@google.com">Ovidio Henriquez</a> (<a class="p-org org" href="https://www.google.com">Google LLC</a>)
     <dt>Participate:
     <dd><a href="https://www.w3.org/community/wicg/">Join the W3C Community Group</a>
     <dd><a href="irc://irc.w3.org:6665/#webusb">IRC: #webusb on W3C’s IRC</a> (Stay around for an answer, it make take a while)
    </dl>
   </div>
   <div data-fill-with="warning"></div>
   <p class="copyright" data-fill-with="copyright"><a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> © 1970 the Contributors to the WebUSB Testing API Specification, published by the <a href="https://www.w3.org/community/wicg/">Web Platform Incubator Community Group</a> under the <a href="https://www.w3.org/community/about/agreements/cla/">W3C Community Contributor License Agreement (CLA)</a>.
A human-readable <a href="http://www.w3.org/community/about/agreements/cla-deed/">summary</a> is available. </p>
   <hr title="Separator for header">
  </div>
  <div class="p-summary" data-fill-with="abstract">
   <h2 class="no-num no-toc no-ref heading settled" id="abstract"><span class="content">Abstract</span></h2>
   <p>This document describes an API for testing a User Agent’s implementation of the WebUSB API.</p>
  </div>
  <div data-fill-with="at-risk"></div>
  <h2 class="no-num no-toc no-ref heading settled" id="status"><span class="content">Status of this document</span></h2>
  <div data-fill-with="status">
   <p> This specification was published by the <a href="https://www.w3.org/community/wicg/">Web Platform Incubator Community Group</a>.
  It is not a W3C Standard nor is it on the W3C Standards Track.

  Please note that under the <a href="https://www.w3.org/community/about/agreements/cla/">W3C Community Contributor License Agreement (CLA)</a> there is a limited opt-out and other conditions apply.

  Learn more about <a href="http://www.w3.org/community/">W3C Community and Business Groups</a>. </p>
   <p></p>
  </div>
  <div data-fill-with="at-risk"></div>
  <nav data-fill-with="table-of-contents" id="toc">
   <h2 class="no-num no-toc no-ref" id="contents">Table of Contents</h2>
   <ol class="toc" role="directory">
    <li>
     <a href="#intro"><span class="secno">1</span> <span class="content">Introduction</span></a>
     <ol class="toc">
      <li><a href="#examples"><span class="secno">1.1</span> <span class="content">Examples</span></a>
     </ol>
    <li><a href="#availability"><span class="secno">2</span> <span class="content">Availability</span></a>
    <li>
     <a href="#test-interface"><span class="secno">3</span> <span class="content">Global Testing Interface</span></a>
     <ol class="toc">
      <li><a href="#usb-behavior"><span class="secno">3.1</span> <span class="content"><code class="idl"><span>USB</span></code> Behavior</span></a>
      <li><a href="#events"><span class="secno">3.2</span> <span class="content">Events</span></a>
     </ol>
    <li>
     <a href="#fake-devices"><span class="secno">4</span> <span class="content">Fake Devices</span></a>
     <ol class="toc">
      <li><a href="#usbdevice-behavior"><span class="secno">4.1</span> <span class="content"><code class="idl"><span>USBDevice</span></code> Behavior</span></a>
     </ol>
    <li><a href="#conformance"><span class="secno"></span> <span class="content"> Conformance</span></a>
    <li>
     <a href="#index"><span class="secno"></span> <span class="content">Index</span></a>
     <ol class="toc">
      <li><a href="#index-defined-here"><span class="secno"></span> <span class="content">Terms defined by this specification</span></a>
      <li><a href="#index-defined-elsewhere"><span class="secno"></span> <span class="content">Terms defined by reference</span></a>
     </ol>
    <li>
     <a href="#references"><span class="secno"></span> <span class="content">References</span></a>
     <ol class="toc">
      <li><a href="#normative"><span class="secno"></span> <span class="content">Normative References</span></a>
     </ol>
    <li><a href="#idl-index"><span class="secno"></span> <span class="content">IDL Index</span></a>
   </ol>
  </nav>
  <main>
   <h2 class="heading settled" data-level="1" id="intro"><span class="secno">1. </span><span class="content">Introduction</span><a class="self-link" href="#intro"></a></h2>
   <p><em>This section is non-normative</em>.</p>
   <p>Standards such as <a data-link-type="biblio" href="#biblio-webusb">[WebUSB]</a> pose a challenge to test authors because to fully
exercise their interfaces requires physical hardware devices that respond in
predictable ways. To address this challenge this specification defines an
interface for controlling a simulation of the USB subsystem on the host the
User Agent (UA) is running on. With this interface devices with particular properties
can be created and their responses to requests are well defined.</p>
   <p>The purpose if this interface is to assist the developers of UAs and so this
interface does not permit arbitrary control over the behavior of devices. Some
parameters are configurable and some are specified.</p>
   <p>The only intended client of this API are tests in <a href="https://github.com/web-platform-tests/wpt">Web Platform Tests</a>.
This testing
API will be changed as needed to support the evolution of those tests.</p>
   <p>Testing applications that use WebUSB is specifically not in scope
for this API. It not designed for that purpose. And, the ability
to make breaking changes to this API has higher priority.</p>
   <h3 class="heading settled" data-level="1.1" id="examples"><span class="secno">1.1. </span><span class="content">Examples</span><a class="self-link" href="#examples"></a></h3>
   <div class="example" id="example-0261f29b">
    <a class="self-link" href="#example-0261f29b"></a> This example, expressed as a W3C testharness.js-based test, demonstrates
initializing this API and using it to verify that devices can be added and
removed. 
<pre>let fakeDeviceInit = {
  usbVersionMajor: 2,
  usbVersionMinor: 0,
  usbVersionSubminor: 0,
  deviceClass: 0xFF,
  deviceSubclass: 0xFF,
  deviceProtocol: 0xFF,
  vendorId: 0x1234,
  productId: 0xABCD,
  deviceVersionMajor: 1,
  deviceVersionMinor: 0,
  deviceVersionSubminor: 0,
  configurations: []
};

function promiseForEvent(eventTarget, eventType) {
  return new Promise(resolve => {
    let eventHandler = evt => {
      resolve(evt);
      eventTarget.removeEventListener(eventTarget, eventHandler);
    };
    eventTarget.addEventListener(eventType);
  });
}

promise_test(async () => {
  await navigator.usb.test.initialize();

  let fakeDevice = navigator.usb.addFakeDevice(fakeDeviceInit);
  let connectEvent = await promiseForEvent(navigator.usb, 'connect');
  let device = connectEvent.device;
  assert_equals(device.usbVersionMajor, fakeDeviceInit.usbVersionMajor);
  assert_equals(device.usbVersionMinor, fakeDeviceInit.usbVersionMinor);
  assert_equals(device.usbVersionSubminor, fakeDeviceInit.usbVersionSubminor);
  assert_equals(device.deviceClass, fakeDeviceInit.deviceClass);
  assert_equals(device.deviceSubclass, fakeDeviceInit.deviceSubclass);
  assert_equals(device.deviceProtocol, fakeDeviceInit.deviceProtocol);
  assert_equals(device.vendorId, fakeDeviceInit.vendorId);
  assert_equals(device.productId, fakeDeviceInit.productId);
  assert_equals(device.deviceVersionMajor, fakeDeviceInit.deviceVersionMajor);
  assert_equals(device.deviceVersionMinor, fakeDeviceInit.deviceVersionMinor);
  assert_equals(device.deviceVersionSubminor, fakeDeviceInit.deviceVersionSubminor);
  assert_equals(device.configuration, null);
  assert_equals(device.configurations.length, 0);

  let devices = await navigator.usb.getDevices();
  assert_array_equals(devices, [device]);

  fakeDevice.disconnect();
  let disconnectEvent = await promiseForEvent(navigator.usb, 'disconnect');
  assert_equals(disconnectEvent.device, device);
});
</pre>
   </div>
   <div class="example" id="example-50660def">
    <a class="self-link" href="#example-50660def"></a> This example, which reuses definitions from the previous example and is also
expressed as a W3C testharness.js-based test, demonstrates a test of the <code>navigator.usb.requestDevice()</code> method. 
<pre>promise_test(async () => {
  await navigator.usb.test.initialize();
  let fakeDevice = navigator.usb.addFakeDevice(fakeDeviceInit);
  let connectEvent = await promiseForEvent(navigator.usb, 'connect');
  navigator.usb.test.onrequestdevice = () => connectEvent.device;

  let options = { filters: [{ vendorId: 0x1234 }] };
  let device = await navigator.usb.requestDevice(options);
  assert_array_equals(navigator.usb.test.lastFilters, options.filters);
  assert_equals(device, connectEvent.device);
}
</pre>
   </div>
   <p class="note" role="note"><span>Note:</span> If multiple tests are run in the same document then the test harness
should invoke <code class="idl"><a data-link-type="idl" href="#dom-usbtest-reset" id="ref-for-dom-usbtest-reset">reset()</a></code> and wait until the <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise">Promise</a></code> it returns is
resolved before executing the next test.</p>
   <h2 class="heading settled" data-level="2" id="availability"><span class="secno">2. </span><span class="content">Availability</span><a class="self-link" href="#availability"></a></h2>
   <p>This specification defines an interface that is not intended be used by
non-testing-related web content. The UA MAY choose to expose this interface
only when a runtime or compile-time flag has been set.</p>
   <div class="note" role="note">
     Note, as an example, in the Chromium Project this specification is implemented
by a JavaScript polyfill on top of a lower-level interface. This interface is
only available in a binary explicitly built for running web platform test cases.
A runtime flag is also necessary to enable this testing mode. This design has
two benefits, 
    <ol>
     <li data-md>
      <p>The risk of introducing a security vulnerability in the default
configuration is mitigated.</p>
     <li data-md>
      <p>The polyfill is not shipped with the production application and so there is
no increase in binary size to support an API that will rarely be used.</p>
    </ol>
   </div>
   <h2 class="heading settled" data-level="3" id="test-interface"><span class="secno">3. </span><span class="content">Global Testing Interface</span><a class="self-link" href="#test-interface"></a></h2>
<pre class="idl highlight def"><c- b>partial</c-> <c- b>interface</c-> <a class="idl-code" data-link-type="interface" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb"><c- g>USB</c-></a> {
  [<a class="idl-code" data-link-type="extended-attribute" href="https://heycam.github.io/webidl/#SameObject" id="ref-for-SameObject"><c- g>SameObject</c-></a>] <c- b>readonly</c-> <c- b>attribute</c-> <a class="n" data-link-type="idl-name" href="#usbtest" id="ref-for-usbtest"><c- n>USBTest</c-></a> <dfn class="idl-code" data-dfn-for="USB" data-dfn-type="attribute" data-export data-readonly data-type="USBTest" id="dom-usb-test"><code><c- g>test</c-></code><a class="self-link" href="#dom-usb-test"></a></dfn>;
};

<c- b>interface</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="interface" data-export id="usbdevicerequestevent"><code><c- g>USBDeviceRequestEvent</c-></code></dfn> : <a class="n" data-link-type="idl-name" href="https://dom.spec.whatwg.org/#event" id="ref-for-event"><c- n>Event</c-></a> {
  <c- b>attribute</c-> <c- b>FrozenArray</c->&lt;<a class="n" data-link-type="idl-name" href="https://wicg.github.io/webusb/#dictdef-usbdevicefilter" id="ref-for-dictdef-usbdevicefilter"><c- n>USBDeviceFilter</c-></a>> <dfn class="idl-code" data-dfn-for="USBDeviceRequestEvent" data-dfn-type="attribute" data-export data-type="FrozenArray<USBDeviceFilter>" id="dom-usbdevicerequestevent-filters"><code><c- g>filters</c-></code><a class="self-link" href="#dom-usbdevicerequestevent-filters"></a></dfn>;

  <c- b>void</c-> <dfn class="dfn-paneled idl-code" data-dfn-for="USBDeviceRequestEvent" data-dfn-type="method" data-export data-lt="respondWith(result)" id="dom-usbdevicerequestevent-respondwith"><code><c- g>respondWith</c-></code></dfn>(<c- b>Promise</c->&lt;<a class="n" data-link-type="idl-name" href="#fakeusbdevice" id="ref-for-fakeusbdevice"><c- n>FakeUSBDevice</c-></a>> <dfn class="idl-code" data-dfn-for="USBDeviceRequestEvent/respondWith(result)" data-dfn-type="argument" data-export id="dom-usbdevicerequestevent-respondwith-result-result"><code><c- g>result</c-></code><a class="self-link" href="#dom-usbdevicerequestevent-respondwith-result-result"></a></dfn>);
};

<c- b>interface</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="interface" data-export id="usbtest"><code><c- g>USBTest</c-></code></dfn> {
  <c- b>attribute</c-> <a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/webappapis.html#eventhandler" id="ref-for-eventhandler"><c- n>EventHandler</c-></a> <dfn class="idl-code" data-dfn-for="USBTest" data-dfn-type="attribute" data-export data-type="EventHandler" id="dom-usbtest-onrequestdevice"><code><c- g>onrequestdevice</c-></code><a class="self-link" href="#dom-usbtest-onrequestdevice"></a></dfn>;

  <c- b>Promise</c->&lt;<c- b>void</c->> <dfn class="dfn-paneled idl-code" data-dfn-for="USBTest" data-dfn-type="method" data-export data-lt="initialize()" id="dom-usbtest-initialize"><code><c- g>initialize</c-></code></dfn>();
  <c- b>Promise</c->&lt;<c- b>void</c->> <dfn class="dfn-paneled idl-code" data-dfn-for="USBTest" data-dfn-type="method" data-export data-lt="attachToContext(context)" id="dom-usbtest-attachtocontext"><code><c- g>attachToContext</c-></code></dfn>((<a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#htmliframeelement" id="ref-for-htmliframeelement"><c- n>HTMLIFrameElement</c-></a> <c- b>or</c-> <a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/workers.html#worker" id="ref-for-worker"><c- n>Worker</c-></a>) <dfn class="idl-code" data-dfn-for="USBTest/attachToContext(context)" data-dfn-type="argument" data-export id="dom-usbtest-attachtocontext-context-context"><code><c- g>context</c-></code><a class="self-link" href="#dom-usbtest-attachtocontext-context-context"></a></dfn>);
  <a class="n" data-link-type="idl-name" href="#fakeusbdevice" id="ref-for-fakeusbdevice①"><c- n>FakeUSBDevice</c-></a> <dfn class="dfn-paneled idl-code" data-dfn-for="USBTest" data-dfn-type="method" data-export data-lt="addFakeDevice(deviceInit)" id="dom-usbtest-addfakedevice"><code><c- g>addFakeDevice</c-></code></dfn>(<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbdeviceinit" id="ref-for-dictdef-fakeusbdeviceinit"><c- n>FakeUSBDeviceInit</c-></a> <dfn class="idl-code" data-dfn-for="USBTest/addFakeDevice(deviceInit)" data-dfn-type="argument" data-export id="dom-usbtest-addfakedevice-deviceinit-deviceinit"><code><c- g>deviceInit</c-></code><a class="self-link" href="#dom-usbtest-addfakedevice-deviceinit-deviceinit"></a></dfn>);
  <c- b>Promise</c->&lt;<c- b>void</c->> <dfn class="dfn-paneled idl-code" data-dfn-for="USBTest" data-dfn-type="method" data-export data-lt="reset()" id="dom-usbtest-reset"><code><c- g>reset</c-></code></dfn>();
};
</pre>
   <p>By default, a UA SHALL NOT alter the behavior of a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb①">USB</a></code> instance <var>usb</var> in any <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/webappapis.html#global-object" id="ref-for-global-object">global object</a> until it is reconfigured so that <var>usb</var> is <dfn class="dfn-paneled" data-dfn-type="dfn" data-lt="controlled by" data-noexport id="controlled-by">controlled
by</dfn> a <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest①">USBTest</a></code> instance <var>test</var>. At that point the behavior of <var>usb</var> is
defined by this specification.</p>
   <p>Instances of <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest②">USBTest</a></code> are created with an <a data-link-type="dfn" href="https://tc39.github.io/ecma262/#sec-object-internal-methods-and-internal-slots" id="ref-for-sec-object-internal-methods-and-internal-slots">internal slot</a> <dfn class="dfn-paneled idl-code" data-dfn-for="USBTest" data-dfn-type="attribute" data-export id="dom-usbtest-initializationpromise-slot"><code>[[initializationPromise]]</code></dfn> with an initial
value of <code>null</code>.</p>
   <p>When invoked, the <code class="idl"><a data-link-type="idl" href="#dom-usbtest-initialize" id="ref-for-dom-usbtest-initialize">initialize()</a></code> method MUST run these steps:</p>
   <ol>
    <li data-md>
     <p>Let <var>test</var> be the <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest③">USBTest</a></code> instance on which this method was invoked.</p>
    <li data-md>
     <p>If <var>test</var>.<code class="idl"><a data-link-type="idl" href="#dom-usbtest-initializationpromise-slot" id="ref-for-dom-usbtest-initializationpromise-slot">[[initializationPromise]]</a></code> is <code>null</code> then
set <var>test</var>.<code class="idl"><a data-link-type="idl" href="#dom-usbtest-initializationpromise-slot" id="ref-for-dom-usbtest-initializationpromise-slot①">[[initializationPromise]]</a></code> to a new <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise①">Promise</a></code> and
run these sub-steps <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel" id="ref-for-in-parallel">in parallel</a>:</p>
     <ol>
      <li data-md>
       <p>Reconfigure the UA’s internal implementation of the <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-navigator-usb" id="ref-for-dom-navigator-usb">usb</a></code> object in the <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/webappapis.html#current-global-object" id="ref-for-current-global-object">current global object</a> so that it is <a data-link-type="dfn" href="#controlled-by" id="ref-for-controlled-by">controlled
by</a> <var>test</var>.</p>
      <li data-md>
       <p><a data-link-type="dfn">Resolve</a> <var>test</var>.<code class="idl"><a data-link-type="idl" href="#dom-usbtest-initializationpromise-slot" id="ref-for-dom-usbtest-initializationpromise-slot②">[[initializationPromise]]</a></code>.</p>
     </ol>
    <li data-md>
     <p>Return <var>test</var>.<code class="idl"><a data-link-type="idl" href="#dom-usbtest-initializationpromise-slot" id="ref-for-dom-usbtest-initializationpromise-slot③">[[initializationPromise]]</a></code>.</p>
   </ol>
   <p>When invoked, the <code class="idl"><a data-link-type="idl" href="#dom-usbtest-attachtocontext" id="ref-for-dom-usbtest-attachtocontext">attachToContext(context)</a></code> method MUST return a new <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise②">Promise</a></code> <var>promise</var> and run these steps <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel" id="ref-for-in-parallel①">in parallel</a>:</p>
   <ol>
    <li data-md>
     <p>Let <var>test</var> be the <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest④">USBTest</a></code> instance on which this method was invoked.</p>
    <li data-md>
     <p>If <var>test</var>.<code class="idl"><a data-link-type="idl" href="#dom-usbtest-initializationpromise-slot" id="ref-for-dom-usbtest-initializationpromise-slot④">[[initializationPromise]]</a></code> is not in the <a data-link-type="dfn">resolved</a> state, reject <var>promise</var> with an <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#invalidstateerror" id="ref-for-invalidstateerror">InvalidStateError</a></code> and
abort these steps.</p>
    <li data-md>
     <p>Reconfigure the UA’s internal implementation of <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-navigator-usb" id="ref-for-dom-navigator-usb①">usb</a></code> in the <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/webappapis.html#global-object" id="ref-for-global-object①">global object</a> associated with <var>context</var> so that it is <a data-link-type="dfn" href="#controlled-by" id="ref-for-controlled-by①">controlled by</a> <var>test</var>.</p>
    <li data-md>
     <p><a data-link-type="dfn">Resolve</a> <var>promise</var>.</p>
   </ol>
   <p>When invoked, the <code class="idl"><a data-link-type="idl" href="#dom-usbtest-addfakedevice" id="ref-for-dom-usbtest-addfakedevice">addFakeDevice(deviceInit)</a></code> method MUST run these
steps:</p>
   <ol>
    <li data-md>
     <p>Let <var>test</var> be the <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest⑤">USBTest</a></code> instance on which this method was invoked.</p>
    <li data-md>
     <p>If <var>test</var>.<code class="idl"><a data-link-type="idl" href="#dom-usbtest-initializationpromise-slot" id="ref-for-dom-usbtest-initializationpromise-slot⑤">[[initializationPromise]]</a></code> is not in the <a data-link-type="dfn">resolved</a> state, raise an <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#invalidstateerror" id="ref-for-invalidstateerror①">InvalidStateError</a></code> and abort these steps.</p>
    <li data-md>
     <p>Let <var>fakeDevice</var> be a new <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice②">FakeUSBDevice</a></code>.</p>
    <li data-md>
     <p><a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/webappapis.html#queue-a-task" id="ref-for-queue-a-task">Queue a task</a> to, for each <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb②">USB</a></code> instance <a data-link-type="dfn" href="#controlled-by" id="ref-for-controlled-by②">controlled by</a> <var>test</var>, perform the steps described in <a data-link-type="biblio" href="#biblio-webusb">[WebUSB]</a> for handling a new device
that is connected to the system.</p>
    <li data-md>
     <p>Return <var>fakeDevice</var>.</p>
   </ol>
   <p>When invoked, the <code class="idl"><a data-link-type="idl" href="#dom-usbtest-reset" id="ref-for-dom-usbtest-reset①">reset()</a></code> method MUST return a new <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise③">Promise</a></code> <var>promise</var> and run the following steps <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel" id="ref-for-in-parallel②">in parallel</a>:</p>
   <ol>
    <li data-md>
     <p>Let <var>test</var> be the <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest⑥">USBTest</a></code> instance on which this method was invoked.</p>
    <li data-md>
     <p>For each <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice③">FakeUSBDevice</a></code> <var>fakeDevice</var> previously returned by <code class="idl"><a data-link-type="idl" href="#dom-usbtest-addfakedevice" id="ref-for-dom-usbtest-addfakedevice①">addFakeDevice()</a></code>, invoke <var>fakeDevice</var>.<code class="idl"><a data-link-type="idl" href="#dom-fakeusbdevice-disconnect" id="ref-for-dom-fakeusbdevice-disconnect">disconnect()</a></code>.</p>
    <li data-md>
     <p><a data-link-type="dfn">Resolve</a> <var>promise</var>.</p>
   </ol>
   <p><code class="idl"><a data-link-type="idl" href="#usbdevicerequestevent" id="ref-for-usbdevicerequestevent">USBDeviceRequestEvent</a></code> instances have an <a data-link-type="dfn" href="https://tc39.github.io/ecma262/#sec-object-internal-methods-and-internal-slots" id="ref-for-sec-object-internal-methods-and-internal-slots①">internal slot</a> <dfn class="dfn-paneled idl-code" data-dfn-for="USBDeviceRequestEvent" data-dfn-type="attribute" data-export id="dom-usbdevicerequestevent-promise-slot"><code>[[promise]]</code></dfn> that holds a <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise④">Promise</a></code>.</p>
   <p>When invoked, the <code class="idl"><a data-link-type="idl" href="#dom-usbdevicerequestevent-respondwith" id="ref-for-dom-usbdevicerequestevent-respondwith">respondWith(result)</a></code> method MUST run
the following steps <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel" id="ref-for-in-parallel③">in parallel</a>:</p>
   <ol>
    <li data-md>
     <p>Wait until <var>result</var> settles.</p>
    <li data-md>
     <p>Let <var>event</var> be the <code class="idl"><a data-link-type="idl" href="#usbdevicerequestevent" id="ref-for-usbdevicerequestevent①">USBDeviceRequestEvent</a></code> instance on which this method
was invoked.</p>
    <li data-md>
     <p>If <var>result</var> resolved with <var>response</var> and <var>response</var> is an instance of <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice④">FakeUSBDevice</a></code> resolve <var>event</var>@<code class="idl"><a data-link-type="idl" href="#dom-usbdevicerequestevent-promise-slot" id="ref-for-dom-usbdevicerequestevent-promise-slot">[[promise]]</a></code> with <var>device</var>.</p>
    <li data-md>
     <p>Otherwise, reject <var>event</var>@<code class="idl"><a data-link-type="idl" href="#dom-usbdevicerequestevent-promise-slot" id="ref-for-dom-usbdevicerequestevent-promise-slot①">[[promise]]</a></code> with a <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#notfounderror" id="ref-for-notfounderror">NotFoundError</a></code>.</p>
   </ol>
   <h3 class="heading settled" data-level="3.1" id="usb-behavior"><span class="secno">3.1. </span><span class="content"><code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb③">USB</a></code> Behavior</span><a class="self-link" href="#usb-behavior"></a></h3>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usb-requestdevice" id="ref-for-dom-usb-requestdevice">requestDevice(options)</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb④">USB</a></code> instance <a data-link-type="dfn" href="#controlled-by" id="ref-for-controlled-by③">controlled by</a> a <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest⑦">USBTest</a></code> <var>test</var> the UA MUST return a new <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-promise" id="ref-for-idl-promise⑤">Promise</a></code> <var>promise</var> and perform the following steps <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel" id="ref-for-in-parallel④">in parallel</a>:</p>
   <ol>
    <li data-md>
     <p>Let <var>event</var> be a new <code class="idl"><a data-link-type="idl" href="#usbdevicerequestevent" id="ref-for-usbdevicerequestevent②">USBDeviceRequestEvent</a></code>.</p>
    <li data-md>
     <p>Set <var>event</var>.<var>filters</var> to a new <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-frozen-array" id="ref-for-idl-frozen-array">FrozenArray</a></code>.</p>
    <li data-md>
     <p>Copy the members of <var>options</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevicerequestoptions-filters" id="ref-for-dom-usbdevicerequestoptions-filters">filters</a></code> into <var>event</var>.<var>filters</var>.</p>
    <li data-md>
     <p>Set <var>event</var>@<code class="idl"><a data-link-type="idl" href="#dom-usbdevicerequestevent-promise-slot" id="ref-for-dom-usbdevicerequestevent-promise-slot②">[[promise]]</a></code> to <var>promise</var>.</p>
    <li data-md>
     <p><a data-link-type="dfn" href="https://dom.spec.whatwg.org/#concept-event-fire" id="ref-for-concept-event-fire">Fire an event</a> named <a data-link-type="dfn" href="#requestdevice" id="ref-for-requestdevice">requestdevice</a> on <var>test</var>, using <var>event</var> as the event object.</p>
   </ol>
   <h3 class="heading settled" data-level="3.2" id="events"><span class="secno">3.2. </span><span class="content">Events</span><a class="self-link" href="#events"></a></h3>
   <p><dfn class="dfn-paneled" data-dfn-type="dfn" data-noexport id="requestdevice">requestdevice</dfn>: Fired on a <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest⑧">USBTest</a></code> object when <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usb-requestdevice" id="ref-for-dom-usb-requestdevice①">requestDevice(options)</a></code> is invoked after <code class="idl"><a data-link-type="idl" href="#dom-usbtest-initialize" id="ref-for-dom-usbtest-initialize①">initialize()</a></code> has
been called.</p>
   <h2 class="heading settled" data-level="4" id="fake-devices"><span class="secno">4. </span><span class="content">Fake Devices</span><a class="self-link" href="#fake-devices"></a></h2>
   <p>To permit testing without physical hardware this specification defines a method
for tests to add simulated USB devices by calling <code class="idl"><a data-link-type="idl" href="#dom-usbtest-addfakedevice" id="ref-for-dom-usbtest-addfakedevice②">addFakeDevice()</a></code> with an instance of <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbdeviceinit" id="ref-for-dictdef-fakeusbdeviceinit①">FakeUSBDeviceInit</a></code> containing the properties of the
device to be added.</p>
<pre class="idl highlight def"><c- b>interface</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="interface" data-export id="fakeusbdevice"><code><c- g>FakeUSBDevice</c-></code></dfn> : <a class="n" data-link-type="idl-name" href="https://dom.spec.whatwg.org/#eventtarget" id="ref-for-eventtarget"><c- n>EventTarget</c-></a> {
  <c- b>attribute</c-> <a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/webappapis.html#eventhandler" id="ref-for-eventhandler①"><c- n>EventHandler</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDevice" data-dfn-type="attribute" data-export data-type="EventHandler" id="dom-fakeusbdevice-onclose"><code><c- g>onclose</c-></code><a class="self-link" href="#dom-fakeusbdevice-onclose"></a></dfn>;

  <c- b>void</c-> <dfn class="dfn-paneled idl-code" data-dfn-for="FakeUSBDevice" data-dfn-type="method" data-export data-lt="disconnect()" id="dom-fakeusbdevice-disconnect"><code><c- g>disconnect</c-></code></dfn>();
};

<c- b>dictionary</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="dictionary" data-export id="dictdef-fakeusbdeviceinit"><code><c- g>FakeUSBDeviceInit</c-></code></dfn> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-usbversionmajor"><code><c- g>usbVersionMajor</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-usbversionmajor"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-usbversionminor"><code><c- g>usbVersionMinor</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-usbversionminor"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet②"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-usbversionsubminor"><code><c- g>usbVersionSubminor</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-usbversionsubminor"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet③"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-deviceclass"><code><c- g>deviceClass</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-deviceclass"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet④"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-devicesubclass"><code><c- g>deviceSubclass</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-devicesubclass"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑤"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-deviceprotocol"><code><c- g>deviceProtocol</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-deviceprotocol"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-unsigned-short" id="ref-for-idl-unsigned-short"><c- b>unsigned</c-> <c- b>short</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="unsigned short " id="dom-fakeusbdeviceinit-vendorid"><code><c- g>vendorId</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-vendorid"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-unsigned-short" id="ref-for-idl-unsigned-short①"><c- b>unsigned</c-> <c- b>short</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="unsigned short " id="dom-fakeusbdeviceinit-productid"><code><c- g>productId</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-productid"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑥"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-deviceversionmajor"><code><c- g>deviceVersionMajor</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-deviceversionmajor"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑦"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-deviceversionminor"><code><c- g>deviceVersionMinor</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-deviceversionminor"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑧"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-deviceversionsubminor"><code><c- g>deviceVersionSubminor</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-deviceversionsubminor"></a></dfn>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString"><c- b>DOMString</c-></a>? <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="DOMString? " id="dom-fakeusbdeviceinit-manufacturername"><code><c- g>manufacturerName</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-manufacturername"></a></dfn>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString①"><c- b>DOMString</c-></a>? <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="DOMString? " id="dom-fakeusbdeviceinit-productname"><code><c- g>productName</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-productname"></a></dfn>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString②"><c- b>DOMString</c-></a>? <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="DOMString? " id="dom-fakeusbdeviceinit-serialnumber"><code><c- g>serialNumber</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-serialnumber"></a></dfn>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑨"><c- b>octet</c-></a> <dfn class="dfn-paneled idl-code" data-default="0" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbdeviceinit-activeconfigurationvalue"><code><c- g>activeConfigurationValue</c-></code></dfn> = 0;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbconfigurationinit" id="ref-for-dictdef-fakeusbconfigurationinit"><c- n>FakeUSBConfigurationInit</c-></a>> <dfn class="idl-code" data-dfn-for="FakeUSBDeviceInit" data-dfn-type="dict-member" data-export data-type="sequence<FakeUSBConfigurationInit> " id="dom-fakeusbdeviceinit-configurations"><code><c- g>configurations</c-></code><a class="self-link" href="#dom-fakeusbdeviceinit-configurations"></a></dfn>;
};

<c- b>dictionary</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="dictionary" data-export id="dictdef-fakeusbconfigurationinit"><code><c- g>FakeUSBConfigurationInit</c-></code></dfn> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⓪"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBConfigurationInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbconfigurationinit-configurationvalue"><code><c- g>configurationValue</c-></code><a class="self-link" href="#dom-fakeusbconfigurationinit-configurationvalue"></a></dfn>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString③"><c- b>DOMString</c-></a>? <dfn class="idl-code" data-dfn-for="FakeUSBConfigurationInit" data-dfn-type="dict-member" data-export data-type="DOMString? " id="dom-fakeusbconfigurationinit-configurationname"><code><c- g>configurationName</c-></code><a class="self-link" href="#dom-fakeusbconfigurationinit-configurationname"></a></dfn>;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbinterfaceinit" id="ref-for-dictdef-fakeusbinterfaceinit"><c- n>FakeUSBInterfaceInit</c-></a>> <dfn class="idl-code" data-dfn-for="FakeUSBConfigurationInit" data-dfn-type="dict-member" data-export data-type="sequence<FakeUSBInterfaceInit> " id="dom-fakeusbconfigurationinit-interfaces"><code><c- g>interfaces</c-></code><a class="self-link" href="#dom-fakeusbconfigurationinit-interfaces"></a></dfn>;
};

<c- b>dictionary</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="dictionary" data-export id="dictdef-fakeusbinterfaceinit"><code><c- g>FakeUSBInterfaceInit</c-></code></dfn> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①①"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBInterfaceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbinterfaceinit-interfacenumber"><code><c- g>interfaceNumber</c-></code><a class="self-link" href="#dom-fakeusbinterfaceinit-interfacenumber"></a></dfn>;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbalternateinterfaceinit" id="ref-for-dictdef-fakeusbalternateinterfaceinit"><c- n>FakeUSBAlternateInterfaceInit</c-></a>> <dfn class="idl-code" data-dfn-for="FakeUSBInterfaceInit" data-dfn-type="dict-member" data-export data-type="sequence<FakeUSBAlternateInterfaceInit> " id="dom-fakeusbinterfaceinit-alternates"><code><c- g>alternates</c-></code><a class="self-link" href="#dom-fakeusbinterfaceinit-alternates"></a></dfn>;
};

<c- b>dictionary</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="dictionary" data-export id="dictdef-fakeusbalternateinterfaceinit"><code><c- g>FakeUSBAlternateInterfaceInit</c-></code></dfn> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①②"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBAlternateInterfaceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbalternateinterfaceinit-alternatesetting"><code><c- g>alternateSetting</c-></code><a class="self-link" href="#dom-fakeusbalternateinterfaceinit-alternatesetting"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①③"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBAlternateInterfaceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbalternateinterfaceinit-interfaceclass"><code><c- g>interfaceClass</c-></code><a class="self-link" href="#dom-fakeusbalternateinterfaceinit-interfaceclass"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①④"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBAlternateInterfaceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbalternateinterfaceinit-interfacesubclass"><code><c- g>interfaceSubclass</c-></code><a class="self-link" href="#dom-fakeusbalternateinterfaceinit-interfacesubclass"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⑤"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBAlternateInterfaceInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbalternateinterfaceinit-interfaceprotocol"><code><c- g>interfaceProtocol</c-></code><a class="self-link" href="#dom-fakeusbalternateinterfaceinit-interfaceprotocol"></a></dfn>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString④"><c- b>DOMString</c-></a>? <dfn class="idl-code" data-dfn-for="FakeUSBAlternateInterfaceInit" data-dfn-type="dict-member" data-export data-type="DOMString? " id="dom-fakeusbalternateinterfaceinit-interfacename"><code><c- g>interfaceName</c-></code><a class="self-link" href="#dom-fakeusbalternateinterfaceinit-interfacename"></a></dfn>;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbendpointinit" id="ref-for-dictdef-fakeusbendpointinit"><c- n>FakeUSBEndpointInit</c-></a>> <dfn class="idl-code" data-dfn-for="FakeUSBAlternateInterfaceInit" data-dfn-type="dict-member" data-export data-type="sequence<FakeUSBEndpointInit> " id="dom-fakeusbalternateinterfaceinit-endpoints"><code><c- g>endpoints</c-></code><a class="self-link" href="#dom-fakeusbalternateinterfaceinit-endpoints"></a></dfn>;
};

<c- b>dictionary</c-> <dfn class="dfn-paneled idl-code" data-dfn-type="dictionary" data-export id="dictdef-fakeusbendpointinit"><code><c- g>FakeUSBEndpointInit</c-></code></dfn> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⑥"><c- b>octet</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBEndpointInit" data-dfn-type="dict-member" data-export data-type="octet " id="dom-fakeusbendpointinit-endpointnumber"><code><c- g>endpointNumber</c-></code><a class="self-link" href="#dom-fakeusbendpointinit-endpointnumber"></a></dfn>;
  <c- b>required</c-> <a class="n" data-link-type="idl-name" href="https://wicg.github.io/webusb/#enumdef-usbdirection" id="ref-for-enumdef-usbdirection"><c- n>USBDirection</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBEndpointInit" data-dfn-type="dict-member" data-export data-type="USBDirection " id="dom-fakeusbendpointinit-direction"><code><c- g>direction</c-></code><a class="self-link" href="#dom-fakeusbendpointinit-direction"></a></dfn>;
  <c- b>required</c-> <a class="n" data-link-type="idl-name" href="https://wicg.github.io/webusb/#enumdef-usbendpointtype" id="ref-for-enumdef-usbendpointtype"><c- n>USBEndpointType</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBEndpointInit" data-dfn-type="dict-member" data-export data-type="USBEndpointType " id="dom-fakeusbendpointinit-type"><code><c- g>type</c-></code><a class="self-link" href="#dom-fakeusbendpointinit-type"></a></dfn>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-unsigned-long" id="ref-for-idl-unsigned-long"><c- b>unsigned</c-> <c- b>long</c-></a> <dfn class="idl-code" data-dfn-for="FakeUSBEndpointInit" data-dfn-type="dict-member" data-export data-type="unsigned long " id="dom-fakeusbendpointinit-packetsize"><code><c- g>packetSize</c-></code><a class="self-link" href="#dom-fakeusbendpointinit-packetsize"></a></dfn>;
};
</pre>
   <p>When a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice">USBDevice</a></code> <var>device</var> is initialized from an fake USB device described
by a <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbdeviceinit" id="ref-for-dictdef-fakeusbdeviceinit②">FakeUSBDeviceInit</a></code> <var>init</var> passed to <code class="idl"><a data-link-type="idl" href="#dom-usbtest-addfakedevice" id="ref-for-dom-usbtest-addfakedevice③">addFakeDevice()</a></code> the
attributes of <var>device</var> SHALL be initialized as follows and <var>device</var> will <dfn class="dfn-paneled" data-dfn-type="dfn" data-local-lt="corresponding to" data-noexport id="correspond-to">correspond to</dfn> the <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice⑤">FakeUSBDevice</a></code> returned by <code class="idl"><a data-link-type="idl" href="#dom-usbtest-addfakedevice" id="ref-for-dom-usbtest-addfakedevice④">addFakeDevice()</a></code>:</p>
   <ol>
    <li data-md>
     <p>For each non-sequence attribute of <var>init</var> other than <code class="idl"><a data-link-type="idl" href="#dom-fakeusbdeviceinit-activeconfigurationvalue" id="ref-for-dom-fakeusbdeviceinit-activeconfigurationvalue">activeConfigurationValue</a></code> the attribute of <var>device</var> with the same name SHALL be set to its value.</p>
    <li data-md>
     <p>For each sequence of <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbconfigurationinit" id="ref-for-dictdef-fakeusbconfigurationinit①">FakeUSBConfigurationInit</a></code>, <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbinterfaceinit" id="ref-for-dictdef-fakeusbinterfaceinit①">FakeUSBInterfaceInit</a></code> <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbalternateinterfaceinit" id="ref-for-dictdef-fakeusbalternateinterfaceinit①">FakeUSBAlternateInterfaceInit</a></code> and <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbendpointinit" id="ref-for-dictdef-fakeusbendpointinit①">FakeUSBEndpointInit</a></code> objects
corresponding <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbconfiguration" id="ref-for-usbconfiguration">USBConfiguration</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbinterface" id="ref-for-usbinterface">USBInterface</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbalternateinterface" id="ref-for-usbalternateinterface">USBAlternateInterface</a></code> and <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbendpoint" id="ref-for-usbendpoint">USBEndpoint</a></code> objects SHALL be created by
similarly copying attributes with the same names and be used to build an
identical hierarchy of objects in the <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-configurations" id="ref-for-dom-usbdevice-configurations">configurations</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbconfiguration-interfaces" id="ref-for-dom-usbconfiguration-interfaces">interfaces</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbinterface-alternates" id="ref-for-dom-usbinterface-alternates">alternates</a></code> and <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbalternateinterface-endpoints" id="ref-for-dom-usbalternateinterface-endpoints">endpoints</a></code> <code class="idl"><a data-link-type="idl" href="https://heycam.github.io/webidl/#idl-frozen-array" id="ref-for-idl-frozen-array①">FrozenArray</a></code>s.</p>
    <li data-md>
     <p>If a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbconfiguration" id="ref-for-usbconfiguration①">USBConfiguration</a></code> instance <var>config</var> with <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbconfiguration-configurationvalue" id="ref-for-dom-usbconfiguration-configurationvalue">configurationValue</a></code> equal to <var>init</var>.<code class="idl"><a data-link-type="idl" href="#dom-fakeusbdeviceinit-activeconfigurationvalue" id="ref-for-dom-fakeusbdeviceinit-activeconfigurationvalue①">activeConfigurationValue</a></code> then <var>device</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-configuration" id="ref-for-dom-usbdevice-configuration">configuration</a></code> SHALL be set to <var>config</var>, otherwise <code>null</code>.</p>
   </ol>
   <p>When invoked, the <code class="idl"><a data-link-type="idl" href="#dom-fakeusbdevice-disconnect" id="ref-for-dom-fakeusbdevice-disconnect①">disconnect()</a></code> method MUST, <a data-link-type="dfn" href="https://html.spec.whatwg.org/multipage/webappapis.html#queue-a-task" id="ref-for-queue-a-task①">queue a task</a> to, for each <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb⑤">USB</a></code> instance <a data-link-type="dfn" href="#controlled-by" id="ref-for-controlled-by④">controlled by</a> the <code class="idl"><a data-link-type="idl" href="#usbtest" id="ref-for-usbtest⑨">USBTest</a></code> instance from which target of this invocation was returned, perform
the steps described in <a data-link-type="biblio" href="#biblio-webusb">[WebUSB]</a> for handling the removal of a device that was
connected to the system.</p>
   <h3 class="heading settled" data-level="4.1" id="usbdevice-behavior"><span class="secno">4.1. </span><span class="content"><code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice①">USBDevice</a></code> Behavior</span><a class="self-link" href="#usbdevice-behavior"></a></h3>
   <p>When the <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-open" id="ref-for-dom-usbdevice-open">open()</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-close" id="ref-for-dom-usbdevice-close">close()</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-selectconfiguration" id="ref-for-dom-usbdevice-selectconfiguration">selectConfiguration()</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-claiminterface" id="ref-for-dom-usbdevice-claiminterface">claimInterface()</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-releaseinterface" id="ref-for-dom-usbdevice-releaseinterface">releaseInterface()</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-selectalternateinterface" id="ref-for-dom-usbdevice-selectalternateinterface">selectAlternateInterface()</a></code>, <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-clearhalt" id="ref-for-dom-usbdevice-clearhalt">clearHalt()</a></code> and <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-reset" id="ref-for-dom-usbdevice-reset">reset()</a></code> methods are invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice②">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice⑥">FakeUSBDevice</a></code> the UA MUST
behave as though <var>device</var> contains the configurations, interfaces and endpoints
described in the <code class="idl"><a data-link-type="idl" href="#dictdef-fakeusbdeviceinit" id="ref-for-dictdef-fakeusbdeviceinit③">FakeUSBDeviceInit</a></code> from which <var>device</var> was initialized exist
and can be claimed by the caller.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-close" id="ref-for-dom-usbdevice-close①">close()</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice③">USBDevice</a></code> <var>device</var> the UA MUST <a data-link-type="dfn" href="https://dom.spec.whatwg.org/#concept-event-fire" id="ref-for-concept-event-fire①">fire an event</a> named <code>close</code> at the <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice⑦">FakeUSBDevice</a></code> instance <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to①">corresponding to</a> <var>device</var>, if one exists.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-controltransferin" id="ref-for-dom-usbdevice-controltransferin">controlTransferIn(setup, length)</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice④">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to②">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice⑧">FakeUSBDevice</a></code> the UA MUST,
assuming all other pre-conditions for the operation are satisfied, behave as
though the device responded with a packet containing the bytes <code>[<var>length</var> >> 8, <var>length</var> &amp; 0xFF, <var>setup</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-request" id="ref-for-dom-usbcontroltransferparameters-request">request</a></code>, <var>setup</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-value" id="ref-for-dom-usbcontroltransferparameters-value">value</a></code> >> 8, <var>setup</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-value" id="ref-for-dom-usbcontroltransferparameters-value①">value</a></code> &amp; 0xFF, <var>setup</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-index" id="ref-for-dom-usbcontroltransferparameters-index">index</a></code> >> 8, <var>setup</var>.<code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-index" id="ref-for-dom-usbcontroltransferparameters-index①">index</a></code> &amp; 0xFF]</code>, truncated to <var>length</var> bytes.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-controltransferout" id="ref-for-dom-usbdevice-controltransferout">controlTransferOut(setup, data)</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice⑤">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to③">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice⑨">FakeUSBDevice</a></code> the UA MUST, assuming all
other pre-conditions for the operation are satisfied, behave as though the
transfer succeeded in sending <var>data</var>.<code>length</code> bytes.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-transferin" id="ref-for-dom-usbdevice-transferin">transferIn(endpointNumber, length)</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice⑥">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to④">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice①⓪">FakeUSBDevice</a></code> the UA MUST,
assuming all other pre-conditions for the operation are satisfied, behave as
though the device responded with <var>length</var> bytes of data consisting of the
values <code>0</code> through <code>255</code> repeated as necessary.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-transferout" id="ref-for-dom-usbdevice-transferout">transferOut(endpointNumber, data)</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice⑦">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to⑤">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice①①">FakeUSBDevice</a></code> the UA MUST,
assuming all other pre-conditions for the operation are satisfied, behave as
though the transfer succeeded in sending <var>data</var>.<code>length</code> bytes.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-isochronoustransferin" id="ref-for-dom-usbdevice-isochronoustransferin">isochronousTransferIn(endpointNumber, packetLengths)</a></code> is
invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice⑧">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to⑥">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice①②">FakeUSBDevice</a></code> the UA MUST, assuming all other pre-conditions for the operation are satisfied,
behave as though the device responded with <var>packetLengths</var>.<code>length</code> packets, each containing <var>packetLengths</var><code>[i]</code> bytes of data consisting of the values <code>0</code> through <code>255</code> repeated as necessary.</p>
   <p>When <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#dom-usbdevice-isochronoustransferout" id="ref-for-dom-usbdevice-isochronoustransferout">isochronousTransferOut(endpointNumber, data, packetLengths)</a></code> is invoked on a <code class="idl"><a data-link-type="idl" href="https://wicg.github.io/webusb/#usbdevice" id="ref-for-usbdevice⑨">USBDevice</a></code> <var>device</var> <a data-link-type="dfn" href="#correspond-to" id="ref-for-correspond-to⑦">corresponding to</a> a <code class="idl"><a data-link-type="idl" href="#fakeusbdevice" id="ref-for-fakeusbdevice①③">FakeUSBDevice</a></code> the UA MUST, assuming all other pre-conditions for the
operation are satisfied, behave as though the transfer succeeded in sending <var>packetLengths</var>.<code>length</code> packets, each containing <var>packetLengths</var><code>[i]</code> bytes.</p>
  </main>
  <div data-fill-with="conformance">
   <h2 class="no-ref no-num heading settled" id="conformance"><span class="content"> Conformance</span><a class="self-link" href="#conformance"></a></h2>
   <p> Conformance requirements are expressed with a combination of descriptive assertions and RFC 2119 terminology.
            The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL”
            in the normative parts of this document
            are to be interpreted as described in RFC 2119.
            However, for readability,
            these words do not appear in all uppercase letters in this specification. </p>
   <p> All of the text of this specification is normative
            except sections explicitly marked as non-normative, examples, and notes. <a data-link-type="biblio" href="#biblio-rfc2119">[RFC2119]</a> </p>
   <p> Examples in this specification are introduced with the words “for example”
            or are set apart from the normative text with <code>class="example"</code>, like this: </p>
   <div class="example" id="example-example"><a class="self-link" href="#example-example"></a> This is an example of an informative example. </div>
   <p> Informative notes begin with the word “Note”
            and are set apart from the normative text with <code>class="note"</code>, like this: </p>
   <p class="note" role="note"> Note, this is an informative note. </p>
  </div>
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  <h2 class="no-num no-ref heading settled" id="index"><span class="content">Index</span><a class="self-link" href="#index"></a></h2>
  <h3 class="no-num no-ref heading settled" id="index-defined-here"><span class="content">Terms defined by this specification</span><a class="self-link" href="#index-defined-here"></a></h3>
  <ul class="index">
   <li><a href="#dom-fakeusbdeviceinit-activeconfigurationvalue">activeConfigurationValue</a><span>, in §4</span>
   <li><a href="#dom-usbtest-addfakedevice">addFakeDevice(deviceInit)</a><span>, in §3</span>
   <li><a href="#dom-fakeusbinterfaceinit-alternates">alternates</a><span>, in §4</span>
   <li><a href="#dom-fakeusbalternateinterfaceinit-alternatesetting">alternateSetting</a><span>, in §4</span>
   <li><a href="#dom-usbtest-attachtocontext">attachToContext(context)</a><span>, in §3</span>
   <li><a href="#dom-fakeusbconfigurationinit-configurationname">configurationName</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-configurations">configurations</a><span>, in §4</span>
   <li><a href="#dom-fakeusbconfigurationinit-configurationvalue">configurationValue</a><span>, in §4</span>
   <li><a href="#controlled-by">controlled by</a><span>, in §3</span>
   <li><a href="#correspond-to">corresponding to</a><span>, in §4</span>
   <li><a href="#correspond-to">correspond to</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-deviceclass">deviceClass</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-deviceprotocol">deviceProtocol</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-devicesubclass">deviceSubclass</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-deviceversionmajor">deviceVersionMajor</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-deviceversionminor">deviceVersionMinor</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-deviceversionsubminor">deviceVersionSubminor</a><span>, in §4</span>
   <li><a href="#dom-fakeusbendpointinit-direction">direction</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdevice-disconnect">disconnect()</a><span>, in §4</span>
   <li><a href="#dom-fakeusbendpointinit-endpointnumber">endpointNumber</a><span>, in §4</span>
   <li><a href="#dom-fakeusbalternateinterfaceinit-endpoints">endpoints</a><span>, in §4</span>
   <li><a href="#dictdef-fakeusbalternateinterfaceinit">FakeUSBAlternateInterfaceInit</a><span>, in §4</span>
   <li><a href="#dictdef-fakeusbconfigurationinit">FakeUSBConfigurationInit</a><span>, in §4</span>
   <li><a href="#fakeusbdevice">FakeUSBDevice</a><span>, in §4</span>
   <li><a href="#dictdef-fakeusbdeviceinit">FakeUSBDeviceInit</a><span>, in §4</span>
   <li><a href="#dictdef-fakeusbendpointinit">FakeUSBEndpointInit</a><span>, in §4</span>
   <li><a href="#dictdef-fakeusbinterfaceinit">FakeUSBInterfaceInit</a><span>, in §4</span>
   <li><a href="#dom-usbdevicerequestevent-filters">filters</a><span>, in §3</span>
   <li><a href="#dom-usbtest-initializationpromise-slot">[[initializationPromise]]</a><span>, in §3</span>
   <li><a href="#dom-usbtest-initialize">initialize()</a><span>, in §3</span>
   <li><a href="#dom-fakeusbalternateinterfaceinit-interfaceclass">interfaceClass</a><span>, in §4</span>
   <li><a href="#dom-fakeusbalternateinterfaceinit-interfacename">interfaceName</a><span>, in §4</span>
   <li><a href="#dom-fakeusbinterfaceinit-interfacenumber">interfaceNumber</a><span>, in §4</span>
   <li><a href="#dom-fakeusbalternateinterfaceinit-interfaceprotocol">interfaceProtocol</a><span>, in §4</span>
   <li><a href="#dom-fakeusbconfigurationinit-interfaces">interfaces</a><span>, in §4</span>
   <li><a href="#dom-fakeusbalternateinterfaceinit-interfacesubclass">interfaceSubclass</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-manufacturername">manufacturerName</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdevice-onclose">onclose</a><span>, in §4</span>
   <li><a href="#dom-usbtest-onrequestdevice">onrequestdevice</a><span>, in §3</span>
   <li><a href="#dom-fakeusbendpointinit-packetsize">packetSize</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-productid">productId</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-productname">productName</a><span>, in §4</span>
   <li><a href="#dom-usbdevicerequestevent-promise-slot">[[promise]]</a><span>, in §3</span>
   <li><a href="#requestdevice">requestdevice</a><span>, in §3.2</span>
   <li><a href="#dom-usbtest-reset">reset()</a><span>, in §3</span>
   <li><a href="#dom-usbdevicerequestevent-respondwith">respondWith(result)</a><span>, in §3</span>
   <li><a href="#dom-fakeusbdeviceinit-serialnumber">serialNumber</a><span>, in §4</span>
   <li><a href="#dom-usb-test">test</a><span>, in §3</span>
   <li><a href="#dom-fakeusbendpointinit-type">type</a><span>, in §4</span>
   <li><a href="#usbdevicerequestevent">USBDeviceRequestEvent</a><span>, in §3</span>
   <li><a href="#usbtest">USBTest</a><span>, in §3</span>
   <li><a href="#dom-fakeusbdeviceinit-usbversionmajor">usbVersionMajor</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-usbversionminor">usbVersionMinor</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-usbversionsubminor">usbVersionSubminor</a><span>, in §4</span>
   <li><a href="#dom-fakeusbdeviceinit-vendorid">vendorId</a><span>, in §4</span>
  </ul>
  <aside class="dfn-panel" data-for="term-for-event">
   <a href="https://dom.spec.whatwg.org/#event">https://dom.spec.whatwg.org/#event</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-event">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-eventtarget">
   <a href="https://dom.spec.whatwg.org/#eventtarget">https://dom.spec.whatwg.org/#eventtarget</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-eventtarget">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-concept-event-fire">
   <a href="https://dom.spec.whatwg.org/#concept-event-fire">https://dom.spec.whatwg.org/#concept-event-fire</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-concept-event-fire">3.1. USB Behavior</a>
    <li><a href="#ref-for-concept-event-fire①">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-sec-object-internal-methods-and-internal-slots">
   <a href="https://tc39.github.io/ecma262/#sec-object-internal-methods-and-internal-slots">https://tc39.github.io/ecma262/#sec-object-internal-methods-and-internal-slots</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-sec-object-internal-methods-and-internal-slots">3. Global Testing Interface</a> <a href="#ref-for-sec-object-internal-methods-and-internal-slots①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-eventhandler">
   <a href="https://html.spec.whatwg.org/multipage/webappapis.html#eventhandler">https://html.spec.whatwg.org/multipage/webappapis.html#eventhandler</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-eventhandler">3. Global Testing Interface</a>
    <li><a href="#ref-for-eventhandler①">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-htmliframeelement">
   <a href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#htmliframeelement">https://html.spec.whatwg.org/multipage/iframe-embed-object.html#htmliframeelement</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-htmliframeelement">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-worker">
   <a href="https://html.spec.whatwg.org/multipage/workers.html#worker">https://html.spec.whatwg.org/multipage/workers.html#worker</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-worker">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-current-global-object">
   <a href="https://html.spec.whatwg.org/multipage/webappapis.html#current-global-object">https://html.spec.whatwg.org/multipage/webappapis.html#current-global-object</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-current-global-object">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-global-object">
   <a href="https://html.spec.whatwg.org/multipage/webappapis.html#global-object">https://html.spec.whatwg.org/multipage/webappapis.html#global-object</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-global-object">3. Global Testing Interface</a> <a href="#ref-for-global-object①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-in-parallel">
   <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel">https://html.spec.whatwg.org/multipage/infrastructure.html#in-parallel</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-in-parallel">3. Global Testing Interface</a> <a href="#ref-for-in-parallel①">(2)</a> <a href="#ref-for-in-parallel②">(3)</a> <a href="#ref-for-in-parallel③">(4)</a>
    <li><a href="#ref-for-in-parallel④">3.1. USB Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-queue-a-task">
   <a href="https://html.spec.whatwg.org/multipage/webappapis.html#queue-a-task">https://html.spec.whatwg.org/multipage/webappapis.html#queue-a-task</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-queue-a-task">3. Global Testing Interface</a>
    <li><a href="#ref-for-queue-a-task①">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-idl-DOMString">
   <a href="https://heycam.github.io/webidl/#idl-DOMString">https://heycam.github.io/webidl/#idl-DOMString</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-idl-DOMString">4. Fake Devices</a> <a href="#ref-for-idl-DOMString①">(2)</a> <a href="#ref-for-idl-DOMString②">(3)</a> <a href="#ref-for-idl-DOMString③">(4)</a> <a href="#ref-for-idl-DOMString④">(5)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-idl-frozen-array">
   <a href="https://heycam.github.io/webidl/#idl-frozen-array">https://heycam.github.io/webidl/#idl-frozen-array</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-idl-frozen-array">3.1. USB Behavior</a>
    <li><a href="#ref-for-idl-frozen-array①">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-invalidstateerror">
   <a href="https://heycam.github.io/webidl/#invalidstateerror">https://heycam.github.io/webidl/#invalidstateerror</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-invalidstateerror">3. Global Testing Interface</a> <a href="#ref-for-invalidstateerror①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-notfounderror">
   <a href="https://heycam.github.io/webidl/#notfounderror">https://heycam.github.io/webidl/#notfounderror</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-notfounderror">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-idl-promise">
   <a href="https://heycam.github.io/webidl/#idl-promise">https://heycam.github.io/webidl/#idl-promise</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-idl-promise">1.1. Examples</a>
    <li><a href="#ref-for-idl-promise①">3. Global Testing Interface</a> <a href="#ref-for-idl-promise②">(2)</a> <a href="#ref-for-idl-promise③">(3)</a> <a href="#ref-for-idl-promise④">(4)</a>
    <li><a href="#ref-for-idl-promise⑤">3.1. USB Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-SameObject">
   <a href="https://heycam.github.io/webidl/#SameObject">https://heycam.github.io/webidl/#SameObject</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-SameObject">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-idl-octet">
   <a href="https://heycam.github.io/webidl/#idl-octet">https://heycam.github.io/webidl/#idl-octet</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-idl-octet">4. Fake Devices</a> <a href="#ref-for-idl-octet①">(2)</a> <a href="#ref-for-idl-octet②">(3)</a> <a href="#ref-for-idl-octet③">(4)</a> <a href="#ref-for-idl-octet④">(5)</a> <a href="#ref-for-idl-octet⑤">(6)</a> <a href="#ref-for-idl-octet⑥">(7)</a> <a href="#ref-for-idl-octet⑦">(8)</a> <a href="#ref-for-idl-octet⑧">(9)</a> <a href="#ref-for-idl-octet⑨">(10)</a> <a href="#ref-for-idl-octet①⓪">(11)</a> <a href="#ref-for-idl-octet①①">(12)</a> <a href="#ref-for-idl-octet①②">(13)</a> <a href="#ref-for-idl-octet①③">(14)</a> <a href="#ref-for-idl-octet①④">(15)</a> <a href="#ref-for-idl-octet①⑤">(16)</a> <a href="#ref-for-idl-octet①⑥">(17)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-idl-unsigned-long">
   <a href="https://heycam.github.io/webidl/#idl-unsigned-long">https://heycam.github.io/webidl/#idl-unsigned-long</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-idl-unsigned-long">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-idl-unsigned-short">
   <a href="https://heycam.github.io/webidl/#idl-unsigned-short">https://heycam.github.io/webidl/#idl-unsigned-short</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-idl-unsigned-short">4. Fake Devices</a> <a href="#ref-for-idl-unsigned-short①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-usb">
   <a href="https://wicg.github.io/webusb/#usb">https://wicg.github.io/webusb/#usb</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usb">3. Global Testing Interface</a> <a href="#ref-for-usb①">(2)</a> <a href="#ref-for-usb②">(3)</a>
    <li><a href="#ref-for-usb③">3.1. USB Behavior</a> <a href="#ref-for-usb④">(2)</a>
    <li><a href="#ref-for-usb⑤">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-usbalternateinterface">
   <a href="https://wicg.github.io/webusb/#usbalternateinterface">https://wicg.github.io/webusb/#usbalternateinterface</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbalternateinterface">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-usbconfiguration">
   <a href="https://wicg.github.io/webusb/#usbconfiguration">https://wicg.github.io/webusb/#usbconfiguration</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbconfiguration">4. Fake Devices</a> <a href="#ref-for-usbconfiguration①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-usbdevice">
   <a href="https://wicg.github.io/webusb/#usbdevice">https://wicg.github.io/webusb/#usbdevice</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbdevice">4. Fake Devices</a>
    <li><a href="#ref-for-usbdevice①">4.1. USBDevice Behavior</a> <a href="#ref-for-usbdevice②">(2)</a> <a href="#ref-for-usbdevice③">(3)</a> <a href="#ref-for-usbdevice④">(4)</a> <a href="#ref-for-usbdevice⑤">(5)</a> <a href="#ref-for-usbdevice⑥">(6)</a> <a href="#ref-for-usbdevice⑦">(7)</a> <a href="#ref-for-usbdevice⑧">(8)</a> <a href="#ref-for-usbdevice⑨">(9)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dictdef-usbdevicefilter">
   <a href="https://wicg.github.io/webusb/#dictdef-usbdevicefilter">https://wicg.github.io/webusb/#dictdef-usbdevicefilter</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dictdef-usbdevicefilter">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-enumdef-usbdirection">
   <a href="https://wicg.github.io/webusb/#enumdef-usbdirection">https://wicg.github.io/webusb/#enumdef-usbdirection</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-enumdef-usbdirection">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-usbendpoint">
   <a href="https://wicg.github.io/webusb/#usbendpoint">https://wicg.github.io/webusb/#usbendpoint</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbendpoint">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-enumdef-usbendpointtype">
   <a href="https://wicg.github.io/webusb/#enumdef-usbendpointtype">https://wicg.github.io/webusb/#enumdef-usbendpointtype</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-enumdef-usbendpointtype">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-usbinterface">
   <a href="https://wicg.github.io/webusb/#usbinterface">https://wicg.github.io/webusb/#usbinterface</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbinterface">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbinterface-alternates">
   <a href="https://wicg.github.io/webusb/#dom-usbinterface-alternates">https://wicg.github.io/webusb/#dom-usbinterface-alternates</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbinterface-alternates">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-claiminterface">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-claiminterface">https://wicg.github.io/webusb/#dom-usbdevice-claiminterface</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-claiminterface">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-clearhalt">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-clearhalt">https://wicg.github.io/webusb/#dom-usbdevice-clearhalt</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-clearhalt">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-close">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-close">https://wicg.github.io/webusb/#dom-usbdevice-close</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-close">4.1. USBDevice Behavior</a> <a href="#ref-for-dom-usbdevice-close①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-configuration">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-configuration">https://wicg.github.io/webusb/#dom-usbdevice-configuration</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-configuration">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbconfiguration-configurationvalue">
   <a href="https://wicg.github.io/webusb/#dom-usbconfiguration-configurationvalue">https://wicg.github.io/webusb/#dom-usbconfiguration-configurationvalue</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbconfiguration-configurationvalue">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-configurations">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-configurations">https://wicg.github.io/webusb/#dom-usbdevice-configurations</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-configurations">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-controltransferin">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-controltransferin">https://wicg.github.io/webusb/#dom-usbdevice-controltransferin</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-controltransferin">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-controltransferout">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-controltransferout">https://wicg.github.io/webusb/#dom-usbdevice-controltransferout</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-controltransferout">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbalternateinterface-endpoints">
   <a href="https://wicg.github.io/webusb/#dom-usbalternateinterface-endpoints">https://wicg.github.io/webusb/#dom-usbalternateinterface-endpoints</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbalternateinterface-endpoints">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevicerequestoptions-filters">
   <a href="https://wicg.github.io/webusb/#dom-usbdevicerequestoptions-filters">https://wicg.github.io/webusb/#dom-usbdevicerequestoptions-filters</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevicerequestoptions-filters">3.1. USB Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbcontroltransferparameters-index">
   <a href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-index">https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-index</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbcontroltransferparameters-index">4.1. USBDevice Behavior</a> <a href="#ref-for-dom-usbcontroltransferparameters-index①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbconfiguration-interfaces">
   <a href="https://wicg.github.io/webusb/#dom-usbconfiguration-interfaces">https://wicg.github.io/webusb/#dom-usbconfiguration-interfaces</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbconfiguration-interfaces">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-isochronoustransferin">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-isochronoustransferin">https://wicg.github.io/webusb/#dom-usbdevice-isochronoustransferin</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-isochronoustransferin">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-isochronoustransferout">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-isochronoustransferout">https://wicg.github.io/webusb/#dom-usbdevice-isochronoustransferout</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-isochronoustransferout">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-open">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-open">https://wicg.github.io/webusb/#dom-usbdevice-open</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-open">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-releaseinterface">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-releaseinterface">https://wicg.github.io/webusb/#dom-usbdevice-releaseinterface</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-releaseinterface">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbcontroltransferparameters-request">
   <a href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-request">https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-request</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbcontroltransferparameters-request">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usb-requestdevice">
   <a href="https://wicg.github.io/webusb/#dom-usb-requestdevice">https://wicg.github.io/webusb/#dom-usb-requestdevice</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usb-requestdevice">3.1. USB Behavior</a>
    <li><a href="#ref-for-dom-usb-requestdevice①">3.2. Events</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-reset">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-reset">https://wicg.github.io/webusb/#dom-usbdevice-reset</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-reset">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-selectalternateinterface">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-selectalternateinterface">https://wicg.github.io/webusb/#dom-usbdevice-selectalternateinterface</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-selectalternateinterface">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-selectconfiguration">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-selectconfiguration">https://wicg.github.io/webusb/#dom-usbdevice-selectconfiguration</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-selectconfiguration">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-transferin">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-transferin">https://wicg.github.io/webusb/#dom-usbdevice-transferin</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-transferin">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbdevice-transferout">
   <a href="https://wicg.github.io/webusb/#dom-usbdevice-transferout">https://wicg.github.io/webusb/#dom-usbdevice-transferout</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevice-transferout">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-navigator-usb">
   <a href="https://wicg.github.io/webusb/#dom-navigator-usb">https://wicg.github.io/webusb/#dom-navigator-usb</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-navigator-usb">3. Global Testing Interface</a> <a href="#ref-for-dom-navigator-usb①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="term-for-dom-usbcontroltransferparameters-value">
   <a href="https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-value">https://wicg.github.io/webusb/#dom-usbcontroltransferparameters-value</a><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbcontroltransferparameters-value">4.1. USBDevice Behavior</a> <a href="#ref-for-dom-usbcontroltransferparameters-value①">(2)</a>
   </ul>
  </aside>
  <h3 class="no-num no-ref heading settled" id="index-defined-elsewhere"><span class="content">Terms defined by reference</span><a class="self-link" href="#index-defined-elsewhere"></a></h3>
  <ul class="index">
   <li>
    <a data-link-type="biblio">[DOM]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-event" style="color:initial">Event</span>
     <li><span class="dfn-paneled" id="term-for-eventtarget" style="color:initial">EventTarget</span>
     <li><span class="dfn-paneled" id="term-for-concept-event-fire" style="color:initial">fire an event</span>
    </ul>
   <li>
    <a data-link-type="biblio">[ECMASCRIPT]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-sec-object-internal-methods-and-internal-slots" style="color:initial">internal slot</span>
    </ul>
   <li>
    <a data-link-type="biblio">[HTML]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-eventhandler" style="color:initial">EventHandler</span>
     <li><span class="dfn-paneled" id="term-for-htmliframeelement" style="color:initial">HTMLIFrameElement</span>
     <li><span class="dfn-paneled" id="term-for-worker" style="color:initial">Worker</span>
     <li><span class="dfn-paneled" id="term-for-current-global-object" style="color:initial">current global object</span>
     <li><span class="dfn-paneled" id="term-for-global-object" style="color:initial">global object</span>
     <li><span class="dfn-paneled" id="term-for-in-parallel" style="color:initial">in parallel</span>
     <li><span class="dfn-paneled" id="term-for-queue-a-task" style="color:initial">queue a task</span>
    </ul>
   <li>
    <a data-link-type="biblio">[WebIDL]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-idl-DOMString" style="color:initial">DOMString</span>
     <li><span class="dfn-paneled" id="term-for-idl-frozen-array" style="color:initial">FrozenArray</span>
     <li><span class="dfn-paneled" id="term-for-invalidstateerror" style="color:initial">InvalidStateError</span>
     <li><span class="dfn-paneled" id="term-for-notfounderror" style="color:initial">NotFoundError</span>
     <li><span class="dfn-paneled" id="term-for-idl-promise" style="color:initial">Promise</span>
     <li><span class="dfn-paneled" id="term-for-SameObject" style="color:initial">SameObject</span>
     <li><span class="dfn-paneled" id="term-for-idl-octet" style="color:initial">octet</span>
     <li><span class="dfn-paneled" id="term-for-idl-unsigned-long" style="color:initial">unsigned long</span>
     <li><span class="dfn-paneled" id="term-for-idl-unsigned-short" style="color:initial">unsigned short</span>
    </ul>
   <li>
    <a data-link-type="biblio">[WebUSB]</a> defines the following terms:
    <ul>
     <li><span class="dfn-paneled" id="term-for-usb" style="color:initial">USB</span>
     <li><span class="dfn-paneled" id="term-for-usbalternateinterface" style="color:initial">USBAlternateInterface</span>
     <li><span class="dfn-paneled" id="term-for-usbconfiguration" style="color:initial">USBConfiguration</span>
     <li><span class="dfn-paneled" id="term-for-usbdevice" style="color:initial">USBDevice</span>
     <li><span class="dfn-paneled" id="term-for-dictdef-usbdevicefilter" style="color:initial">USBDeviceFilter</span>
     <li><span class="dfn-paneled" id="term-for-enumdef-usbdirection" style="color:initial">USBDirection</span>
     <li><span class="dfn-paneled" id="term-for-usbendpoint" style="color:initial">USBEndpoint</span>
     <li><span class="dfn-paneled" id="term-for-enumdef-usbendpointtype" style="color:initial">USBEndpointType</span>
     <li><span class="dfn-paneled" id="term-for-usbinterface" style="color:initial">USBInterface</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbinterface-alternates" style="color:initial">alternates</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-claiminterface" style="color:initial">claimInterface(interfaceNumber)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-clearhalt" style="color:initial">clearHalt(direction, endpointNumber)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-close" style="color:initial">close()</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-configuration" style="color:initial">configuration</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbconfiguration-configurationvalue" style="color:initial">configurationValue</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-configurations" style="color:initial">configurations</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-controltransferin" style="color:initial">controlTransferIn(setup, length)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-controltransferout" style="color:initial">controlTransferOut(setup, data)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbalternateinterface-endpoints" style="color:initial">endpoints</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevicerequestoptions-filters" style="color:initial">filters</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbcontroltransferparameters-index" style="color:initial">index</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbconfiguration-interfaces" style="color:initial">interfaces</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-isochronoustransferin" style="color:initial">isochronousTransferIn(endpointNumber, packetLengths)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-isochronoustransferout" style="color:initial">isochronousTransferOut(endpointNumber, data, packetLengths)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-open" style="color:initial">open()</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-releaseinterface" style="color:initial">releaseInterface(interfaceNumber)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbcontroltransferparameters-request" style="color:initial">request</span>
     <li><span class="dfn-paneled" id="term-for-dom-usb-requestdevice" style="color:initial">requestDevice(options)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-reset" style="color:initial">reset()</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-selectalternateinterface" style="color:initial">selectAlternateInterface(interfaceNumber, alternateSetting)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-selectconfiguration" style="color:initial">selectConfiguration(configurationValue)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-transferin" style="color:initial">transferIn(endpointNumber, length)</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbdevice-transferout" style="color:initial">transferOut(endpointNumber, data)</span>
     <li><span class="dfn-paneled" id="term-for-dom-navigator-usb" style="color:initial">usb</span>
     <li><span class="dfn-paneled" id="term-for-dom-usbcontroltransferparameters-value" style="color:initial">value</span>
    </ul>
  </ul>
  <h2 class="no-num no-ref heading settled" id="references"><span class="content">References</span><a class="self-link" href="#references"></a></h2>
  <h3 class="no-num no-ref heading settled" id="normative"><span class="content">Normative References</span><a class="self-link" href="#normative"></a></h3>
  <dl>
   <dt id="biblio-dom">[DOM]
   <dd>Anne van Kesteren. <a href="https://dom.spec.whatwg.org/">DOM Standard</a>. Living Standard. URL: <a href="https://dom.spec.whatwg.org/">https://dom.spec.whatwg.org/</a>
   <dt id="biblio-ecmascript">[ECMASCRIPT]
   <dd><a href="https://tc39.github.io/ecma262/">ECMAScript Language Specification</a>. URL: <a href="https://tc39.github.io/ecma262/">https://tc39.github.io/ecma262/</a>
   <dt id="biblio-html">[HTML]
   <dd>Anne van Kesteren; et al. <a href="https://html.spec.whatwg.org/multipage/">HTML Standard</a>. Living Standard. URL: <a href="https://html.spec.whatwg.org/multipage/">https://html.spec.whatwg.org/multipage/</a>
   <dt id="biblio-rfc2119">[RFC2119]
   <dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119">Key words for use in RFCs to Indicate Requirement Levels</a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119">https://tools.ietf.org/html/rfc2119</a>
   <dt id="biblio-webidl">[WebIDL]
   <dd>Boris Zbarsky. <a href="https://heycam.github.io/webidl/">Web IDL</a>. 15 December 2016. ED. URL: <a href="https://heycam.github.io/webidl/">https://heycam.github.io/webidl/</a>
   <dt id="biblio-webusb">[WebUSB]
   <dd><a href="https://wicg.github.io/webusb/">WebUSB API</a>. Living Standard. URL: <a href="https://wicg.github.io/webusb/">https://wicg.github.io/webusb/</a>
  </dl>
  <h2 class="no-num no-ref heading settled" id="idl-index"><span class="content">IDL Index</span><a class="self-link" href="#idl-index"></a></h2>
<pre class="idl highlight def"><c- b>partial</c-> <c- b>interface</c-> <a class="idl-code" data-link-type="interface" href="https://wicg.github.io/webusb/#usb" id="ref-for-usb⑥"><c- g>USB</c-></a> {
  [<a class="idl-code" data-link-type="extended-attribute" href="https://heycam.github.io/webidl/#SameObject" id="ref-for-SameObject①"><c- g>SameObject</c-></a>] <c- b>readonly</c-> <c- b>attribute</c-> <a class="n" data-link-type="idl-name" href="#usbtest" id="ref-for-usbtest①⓪"><c- n>USBTest</c-></a> <a data-readonly data-type="USBTest" href="#dom-usb-test"><code><c- g>test</c-></code></a>;
};

<c- b>interface</c-> <a href="#usbdevicerequestevent"><code><c- g>USBDeviceRequestEvent</c-></code></a> : <a class="n" data-link-type="idl-name" href="https://dom.spec.whatwg.org/#event" id="ref-for-event①"><c- n>Event</c-></a> {
  <c- b>attribute</c-> <c- b>FrozenArray</c->&lt;<a class="n" data-link-type="idl-name" href="https://wicg.github.io/webusb/#dictdef-usbdevicefilter" id="ref-for-dictdef-usbdevicefilter①"><c- n>USBDeviceFilter</c-></a>> <a data-type="FrozenArray<USBDeviceFilter>" href="#dom-usbdevicerequestevent-filters"><code><c- g>filters</c-></code></a>;

  <c- b>void</c-> <a href="#dom-usbdevicerequestevent-respondwith"><code><c- g>respondWith</c-></code></a>(<c- b>Promise</c->&lt;<a class="n" data-link-type="idl-name" href="#fakeusbdevice" id="ref-for-fakeusbdevice①④"><c- n>FakeUSBDevice</c-></a>> <a href="#dom-usbdevicerequestevent-respondwith-result-result"><code><c- g>result</c-></code></a>);
};

<c- b>interface</c-> <a href="#usbtest"><code><c- g>USBTest</c-></code></a> {
  <c- b>attribute</c-> <a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/webappapis.html#eventhandler" id="ref-for-eventhandler②"><c- n>EventHandler</c-></a> <a data-type="EventHandler" href="#dom-usbtest-onrequestdevice"><code><c- g>onrequestdevice</c-></code></a>;

  <c- b>Promise</c->&lt;<c- b>void</c->> <a href="#dom-usbtest-initialize"><code><c- g>initialize</c-></code></a>();
  <c- b>Promise</c->&lt;<c- b>void</c->> <a href="#dom-usbtest-attachtocontext"><code><c- g>attachToContext</c-></code></a>((<a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#htmliframeelement" id="ref-for-htmliframeelement①"><c- n>HTMLIFrameElement</c-></a> <c- b>or</c-> <a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/workers.html#worker" id="ref-for-worker①"><c- n>Worker</c-></a>) <a href="#dom-usbtest-attachtocontext-context-context"><code><c- g>context</c-></code></a>);
  <a class="n" data-link-type="idl-name" href="#fakeusbdevice" id="ref-for-fakeusbdevice①⑤"><c- n>FakeUSBDevice</c-></a> <a href="#dom-usbtest-addfakedevice"><code><c- g>addFakeDevice</c-></code></a>(<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbdeviceinit" id="ref-for-dictdef-fakeusbdeviceinit④"><c- n>FakeUSBDeviceInit</c-></a> <a href="#dom-usbtest-addfakedevice-deviceinit-deviceinit"><code><c- g>deviceInit</c-></code></a>);
  <c- b>Promise</c->&lt;<c- b>void</c->> <a href="#dom-usbtest-reset"><code><c- g>reset</c-></code></a>();
};

<c- b>interface</c-> <a href="#fakeusbdevice"><code><c- g>FakeUSBDevice</c-></code></a> : <a class="n" data-link-type="idl-name" href="https://dom.spec.whatwg.org/#eventtarget" id="ref-for-eventtarget①"><c- n>EventTarget</c-></a> {
  <c- b>attribute</c-> <a class="n" data-link-type="idl-name" href="https://html.spec.whatwg.org/multipage/webappapis.html#eventhandler" id="ref-for-eventhandler①①"><c- n>EventHandler</c-></a> <a data-type="EventHandler" href="#dom-fakeusbdevice-onclose"><code><c- g>onclose</c-></code></a>;

  <c- b>void</c-> <a href="#dom-fakeusbdevice-disconnect"><code><c- g>disconnect</c-></code></a>();
};

<c- b>dictionary</c-> <a href="#dictdef-fakeusbdeviceinit"><code><c- g>FakeUSBDeviceInit</c-></code></a> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⑧"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-usbversionmajor"><code><c- g>usbVersionMajor</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⑦"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-usbversionminor"><code><c- g>usbVersionMinor</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet②①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-usbversionsubminor"><code><c- g>usbVersionSubminor</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet③①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-deviceclass"><code><c- g>deviceClass</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet④①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-devicesubclass"><code><c- g>deviceSubclass</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑤①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-deviceprotocol"><code><c- g>deviceProtocol</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-unsigned-short" id="ref-for-idl-unsigned-short②"><c- b>unsigned</c-> <c- b>short</c-></a> <a data-type="unsigned short " href="#dom-fakeusbdeviceinit-vendorid"><code><c- g>vendorId</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-unsigned-short" id="ref-for-idl-unsigned-short①①"><c- b>unsigned</c-> <c- b>short</c-></a> <a data-type="unsigned short " href="#dom-fakeusbdeviceinit-productid"><code><c- g>productId</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑥①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-deviceversionmajor"><code><c- g>deviceVersionMajor</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑦①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-deviceversionminor"><code><c- g>deviceVersionMinor</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑧①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbdeviceinit-deviceversionsubminor"><code><c- g>deviceVersionSubminor</c-></code></a>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString⑤"><c- b>DOMString</c-></a>? <a data-type="DOMString? " href="#dom-fakeusbdeviceinit-manufacturername"><code><c- g>manufacturerName</c-></code></a>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString①①"><c- b>DOMString</c-></a>? <a data-type="DOMString? " href="#dom-fakeusbdeviceinit-productname"><code><c- g>productName</c-></code></a>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString②①"><c- b>DOMString</c-></a>? <a data-type="DOMString? " href="#dom-fakeusbdeviceinit-serialnumber"><code><c- g>serialNumber</c-></code></a>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet⑨①"><c- b>octet</c-></a> <a data-default="0" data-type="octet " href="#dom-fakeusbdeviceinit-activeconfigurationvalue"><code><c- g>activeConfigurationValue</c-></code></a> = 0;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbconfigurationinit" id="ref-for-dictdef-fakeusbconfigurationinit②"><c- n>FakeUSBConfigurationInit</c-></a>> <a data-type="sequence<FakeUSBConfigurationInit> " href="#dom-fakeusbdeviceinit-configurations"><code><c- g>configurations</c-></code></a>;
};

<c- b>dictionary</c-> <a href="#dictdef-fakeusbconfigurationinit"><code><c- g>FakeUSBConfigurationInit</c-></code></a> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⓪①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbconfigurationinit-configurationvalue"><code><c- g>configurationValue</c-></code></a>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString③①"><c- b>DOMString</c-></a>? <a data-type="DOMString? " href="#dom-fakeusbconfigurationinit-configurationname"><code><c- g>configurationName</c-></code></a>;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbinterfaceinit" id="ref-for-dictdef-fakeusbinterfaceinit②"><c- n>FakeUSBInterfaceInit</c-></a>> <a data-type="sequence<FakeUSBInterfaceInit> " href="#dom-fakeusbconfigurationinit-interfaces"><code><c- g>interfaces</c-></code></a>;
};

<c- b>dictionary</c-> <a href="#dictdef-fakeusbinterfaceinit"><code><c- g>FakeUSBInterfaceInit</c-></code></a> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①①①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbinterfaceinit-interfacenumber"><code><c- g>interfaceNumber</c-></code></a>;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbalternateinterfaceinit" id="ref-for-dictdef-fakeusbalternateinterfaceinit②"><c- n>FakeUSBAlternateInterfaceInit</c-></a>> <a data-type="sequence<FakeUSBAlternateInterfaceInit> " href="#dom-fakeusbinterfaceinit-alternates"><code><c- g>alternates</c-></code></a>;
};

<c- b>dictionary</c-> <a href="#dictdef-fakeusbalternateinterfaceinit"><code><c- g>FakeUSBAlternateInterfaceInit</c-></code></a> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①②①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbalternateinterfaceinit-alternatesetting"><code><c- g>alternateSetting</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①③①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbalternateinterfaceinit-interfaceclass"><code><c- g>interfaceClass</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①④①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbalternateinterfaceinit-interfacesubclass"><code><c- g>interfaceSubclass</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⑤①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbalternateinterfaceinit-interfaceprotocol"><code><c- g>interfaceProtocol</c-></code></a>;
  <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-DOMString" id="ref-for-idl-DOMString④①"><c- b>DOMString</c-></a>? <a data-type="DOMString? " href="#dom-fakeusbalternateinterfaceinit-interfacename"><code><c- g>interfaceName</c-></code></a>;
  <c- b>sequence</c->&lt;<a class="n" data-link-type="idl-name" href="#dictdef-fakeusbendpointinit" id="ref-for-dictdef-fakeusbendpointinit②"><c- n>FakeUSBEndpointInit</c-></a>> <a data-type="sequence<FakeUSBEndpointInit> " href="#dom-fakeusbalternateinterfaceinit-endpoints"><code><c- g>endpoints</c-></code></a>;
};

<c- b>dictionary</c-> <a href="#dictdef-fakeusbendpointinit"><code><c- g>FakeUSBEndpointInit</c-></code></a> {
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-octet" id="ref-for-idl-octet①⑥①"><c- b>octet</c-></a> <a data-type="octet " href="#dom-fakeusbendpointinit-endpointnumber"><code><c- g>endpointNumber</c-></code></a>;
  <c- b>required</c-> <a class="n" data-link-type="idl-name" href="https://wicg.github.io/webusb/#enumdef-usbdirection" id="ref-for-enumdef-usbdirection①"><c- n>USBDirection</c-></a> <a data-type="USBDirection " href="#dom-fakeusbendpointinit-direction"><code><c- g>direction</c-></code></a>;
  <c- b>required</c-> <a class="n" data-link-type="idl-name" href="https://wicg.github.io/webusb/#enumdef-usbendpointtype" id="ref-for-enumdef-usbendpointtype①"><c- n>USBEndpointType</c-></a> <a data-type="USBEndpointType " href="#dom-fakeusbendpointinit-type"><code><c- g>type</c-></code></a>;
  <c- b>required</c-> <a class="idl-code" data-link-type="interface" href="https://heycam.github.io/webidl/#idl-unsigned-long" id="ref-for-idl-unsigned-long①"><c- b>unsigned</c-> <c- b>long</c-></a> <a data-type="unsigned long " href="#dom-fakeusbendpointinit-packetsize"><code><c- g>packetSize</c-></code></a>;
};

</pre>
  <aside class="dfn-panel" data-for="usbdevicerequestevent">
   <b><a href="#usbdevicerequestevent">#usbdevicerequestevent</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbdevicerequestevent">3. Global Testing Interface</a> <a href="#ref-for-usbdevicerequestevent①">(2)</a>
    <li><a href="#ref-for-usbdevicerequestevent②">3.1. USB Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbdevicerequestevent-respondwith">
   <b><a href="#dom-usbdevicerequestevent-respondwith">#dom-usbdevicerequestevent-respondwith</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevicerequestevent-respondwith">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="usbtest">
   <b><a href="#usbtest">#usbtest</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-usbtest">3. Global Testing Interface</a> <a href="#ref-for-usbtest①">(2)</a> <a href="#ref-for-usbtest②">(3)</a> <a href="#ref-for-usbtest③">(4)</a> <a href="#ref-for-usbtest④">(5)</a> <a href="#ref-for-usbtest⑤">(6)</a> <a href="#ref-for-usbtest⑥">(7)</a>
    <li><a href="#ref-for-usbtest⑦">3.1. USB Behavior</a>
    <li><a href="#ref-for-usbtest⑧">3.2. Events</a>
    <li><a href="#ref-for-usbtest⑨">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbtest-initialize">
   <b><a href="#dom-usbtest-initialize">#dom-usbtest-initialize</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbtest-initialize">3. Global Testing Interface</a>
    <li><a href="#ref-for-dom-usbtest-initialize①">3.2. Events</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbtest-attachtocontext">
   <b><a href="#dom-usbtest-attachtocontext">#dom-usbtest-attachtocontext</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbtest-attachtocontext">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbtest-addfakedevice">
   <b><a href="#dom-usbtest-addfakedevice">#dom-usbtest-addfakedevice</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbtest-addfakedevice">3. Global Testing Interface</a> <a href="#ref-for-dom-usbtest-addfakedevice①">(2)</a>
    <li><a href="#ref-for-dom-usbtest-addfakedevice②">4. Fake Devices</a> <a href="#ref-for-dom-usbtest-addfakedevice③">(2)</a> <a href="#ref-for-dom-usbtest-addfakedevice④">(3)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbtest-reset">
   <b><a href="#dom-usbtest-reset">#dom-usbtest-reset</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbtest-reset">1.1. Examples</a>
    <li><a href="#ref-for-dom-usbtest-reset①">3. Global Testing Interface</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="controlled-by">
   <b><a href="#controlled-by">#controlled-by</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-controlled-by">3. Global Testing Interface</a> <a href="#ref-for-controlled-by①">(2)</a> <a href="#ref-for-controlled-by②">(3)</a>
    <li><a href="#ref-for-controlled-by③">3.1. USB Behavior</a>
    <li><a href="#ref-for-controlled-by④">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbtest-initializationpromise-slot">
   <b><a href="#dom-usbtest-initializationpromise-slot">#dom-usbtest-initializationpromise-slot</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbtest-initializationpromise-slot">3. Global Testing Interface</a> <a href="#ref-for-dom-usbtest-initializationpromise-slot①">(2)</a> <a href="#ref-for-dom-usbtest-initializationpromise-slot②">(3)</a> <a href="#ref-for-dom-usbtest-initializationpromise-slot③">(4)</a> <a href="#ref-for-dom-usbtest-initializationpromise-slot④">(5)</a> <a href="#ref-for-dom-usbtest-initializationpromise-slot⑤">(6)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-usbdevicerequestevent-promise-slot">
   <b><a href="#dom-usbdevicerequestevent-promise-slot">#dom-usbdevicerequestevent-promise-slot</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-usbdevicerequestevent-promise-slot">3. Global Testing Interface</a> <a href="#ref-for-dom-usbdevicerequestevent-promise-slot①">(2)</a>
    <li><a href="#ref-for-dom-usbdevicerequestevent-promise-slot②">3.1. USB Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="requestdevice">
   <b><a href="#requestdevice">#requestdevice</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-requestdevice">3.1. USB Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="fakeusbdevice">
   <b><a href="#fakeusbdevice">#fakeusbdevice</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-fakeusbdevice">3. Global Testing Interface</a> <a href="#ref-for-fakeusbdevice①">(2)</a> <a href="#ref-for-fakeusbdevice②">(3)</a> <a href="#ref-for-fakeusbdevice③">(4)</a> <a href="#ref-for-fakeusbdevice④">(5)</a>
    <li><a href="#ref-for-fakeusbdevice⑤">4. Fake Devices</a>
    <li><a href="#ref-for-fakeusbdevice⑥">4.1. USBDevice Behavior</a> <a href="#ref-for-fakeusbdevice⑦">(2)</a> <a href="#ref-for-fakeusbdevice⑧">(3)</a> <a href="#ref-for-fakeusbdevice⑨">(4)</a> <a href="#ref-for-fakeusbdevice①⓪">(5)</a> <a href="#ref-for-fakeusbdevice①①">(6)</a> <a href="#ref-for-fakeusbdevice①②">(7)</a> <a href="#ref-for-fakeusbdevice①③">(8)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-fakeusbdevice-disconnect">
   <b><a href="#dom-fakeusbdevice-disconnect">#dom-fakeusbdevice-disconnect</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-fakeusbdevice-disconnect">3. Global Testing Interface</a>
    <li><a href="#ref-for-dom-fakeusbdevice-disconnect①">4. Fake Devices</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dictdef-fakeusbdeviceinit">
   <b><a href="#dictdef-fakeusbdeviceinit">#dictdef-fakeusbdeviceinit</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dictdef-fakeusbdeviceinit">3. Global Testing Interface</a>
    <li><a href="#ref-for-dictdef-fakeusbdeviceinit①">4. Fake Devices</a> <a href="#ref-for-dictdef-fakeusbdeviceinit②">(2)</a>
    <li><a href="#ref-for-dictdef-fakeusbdeviceinit③">4.1. USBDevice Behavior</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dom-fakeusbdeviceinit-activeconfigurationvalue">
   <b><a href="#dom-fakeusbdeviceinit-activeconfigurationvalue">#dom-fakeusbdeviceinit-activeconfigurationvalue</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dom-fakeusbdeviceinit-activeconfigurationvalue">4. Fake Devices</a> <a href="#ref-for-dom-fakeusbdeviceinit-activeconfigurationvalue①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dictdef-fakeusbconfigurationinit">
   <b><a href="#dictdef-fakeusbconfigurationinit">#dictdef-fakeusbconfigurationinit</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dictdef-fakeusbconfigurationinit">4. Fake Devices</a> <a href="#ref-for-dictdef-fakeusbconfigurationinit①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dictdef-fakeusbinterfaceinit">
   <b><a href="#dictdef-fakeusbinterfaceinit">#dictdef-fakeusbinterfaceinit</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dictdef-fakeusbinterfaceinit">4. Fake Devices</a> <a href="#ref-for-dictdef-fakeusbinterfaceinit①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dictdef-fakeusbalternateinterfaceinit">
   <b><a href="#dictdef-fakeusbalternateinterfaceinit">#dictdef-fakeusbalternateinterfaceinit</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dictdef-fakeusbalternateinterfaceinit">4. Fake Devices</a> <a href="#ref-for-dictdef-fakeusbalternateinterfaceinit①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="dictdef-fakeusbendpointinit">
   <b><a href="#dictdef-fakeusbendpointinit">#dictdef-fakeusbendpointinit</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-dictdef-fakeusbendpointinit">4. Fake Devices</a> <a href="#ref-for-dictdef-fakeusbendpointinit①">(2)</a>
   </ul>
  </aside>
  <aside class="dfn-panel" data-for="correspond-to">
   <b><a href="#correspond-to">#correspond-to</a></b><b>Referenced in:</b>
   <ul>
    <li><a href="#ref-for-correspond-to">4.1. USBDevice Behavior</a> <a href="#ref-for-correspond-to①">(2)</a> <a href="#ref-for-correspond-to②">(3)</a> <a href="#ref-for-correspond-to③">(4)</a> <a href="#ref-for-correspond-to④">(5)</a> <a href="#ref-for-correspond-to⑤">(6)</a> <a href="#ref-for-correspond-to⑥">(7)</a> <a href="#ref-for-correspond-to⑦">(8)</a>
   </ul>
  </aside>
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